var dhtmlhisfile={};
window.dhtmlHistory = {
	 initialize: function() 
	 {
			if (this.isInternetExplorer() == false) 
				return;
						
			if (historyStorage.hasKey("DhtmlHistory_pageLoaded") == false) 
			{
					this.fireOnNewListener = false;
					this.firstLoad = true;
					historyStorage.put("DhtmlHistory_pageLoaded", true);
			}
			else 
			{
					this.fireOnNewListener = true;
					this.firstLoad = false;
			}
	 },
                        
						
	 addListener: function(callback) 
	 {
			this.listener = callback;
			if (this.fireOnNewListener == true) 
			{
						this.fireHistoryEvent(this.currentLocation);
						this.fireOnNewListener = false;
			}
	 },




/** public */ add: function(newLocation, historyData,newfile) 
			{
					
	/*				var expohis;
	
			    expohis=	newLocation.split('QHISQ');
				newLocation = expohis[1];	*/
					
					// most browsers require that we wait a certain amount of time before changing the
				// location, such as 200 milliseconds; rather than forcing external callers to use
				// window.setTimeout to account for this to prevent bugs, we internally handle this
				// detail by using a 'currentWaitTime' variable and have requests wait in line
				var self = this;
				
					var addImpl = function() 
					{
							// indicate that the current wait time is now less
					if (self.currentWaitTime > 0)
									self.currentWaitTime = self.currentWaitTime - self.WAIT_TIME;
			
							// remove any leading hash symbols on newLocation
					newLocation = self.removeHash(newLocation);

			
							// IE has a strange bug; if the newLocation
					// is the same as _any_ preexisting id in the
					// document, then the history action gets recorded
					// twice; throw a programmer exception if there is
					// an element with this ID
					var idCheck = document.getElementById(newLocation);
					
							if (idCheck != undefined || idCheck != null) 
							{
									var message = 
									"Exception: History locations can not have "
									+ "the same value as _any_ id's "
									+ "that might be in the document, "
									+ "due to a bug in Internet "
									+ "Explorer; please ask the "
									+ "developer to choose a history "
									+ "location that does not match "
									+ "any HTML id's in this "
									+ "document. The following ID "
									+ "is already taken and can not "
									+ "be a location: " 
									+ newLocation;
									
									throw message; 
							}
							
							// store the history data into history storage
					historyStorage.put(newLocation, historyData);
							
							// indicate to the browser to ignore this upcomming 
					// location change
					self.ignoreLocationChange = true;
			 
							// indicate to IE that this is an atomic location change
					// block
					this.ieAtomicLocationChange = true;
											
							// save this as our current location
					self.currentLocation = newLocation;
							
							// change the browser location

					dhtmlhisfile[newLocation]=newfile;
					window.location.hash = newLocation;
							
							// change the hidden iframe's location if on IE
					if (self.isInternetExplorer())
					{
					//	alert(newLocation);
							self.iframe.src = "blank.html?" + newLocation;
							//alert(self.iframe.src);
					}
					
							// end of atomic location change block
					// for IE
					this.ieAtomicLocationChange = false;
					};
			
					// now execute this add request after waiting a certain amount of time, so as to
				// queue up requests
				window.setTimeout(addImpl, this.currentWaitTime);
			
					// indicate that the next request will have to wait for awhile
				this.currentWaitTime = this.currentWaitTime + this.WAIT_TIME;
			},





/** public */ isFirstLoad: function() 
			{
					if (this.firstLoad == true) {
							return true;
					}
					else {
							return false;
					}
			},



/** public */ isInternational: function() 
			{
					return false;
			},



/** public */ getVersion: function() 
			{
					return "0.05";
			},



			/** Gets the current hash value that is in the browser's
					location bar, removing leading # symbols if they are present. */
/** public */ getCurrentLocation: function() 
			{
					var currentLocation = this.removeHash(window.location.hash);
							
					return currentLocation;
			},


/** Our current hash location, without the "#" symbol. */
/** private */ currentLocation: null,

/** Our history change listener. */
/** private */ listener: null,

/** A hidden IFrame we use in Internet Explorer to detect history
        changes. */
/** private */ iframe: null,

/** Indicates to the browser whether to ignore location changes. */
/** private */ ignoreLocationChange: null,
 
/** The amount of time in milliseconds that we should wait between add requests. 
        Firefox is okay with 200 ms, but Internet Explorer needs 400. */
/** private */ WAIT_TIME: 200,

/** The amount of time in milliseconds an add request has to wait in line before being
        run on a window.setTimeout. */
/** private */ currentWaitTime: 0,

/** A flag that indicates that we should fire a history change event
        when we are ready, i.e. after we are initialized and
        we have a history change listener. This is needed due to 
        an edge case in browsers other than Internet Explorer; if
        you leave a page entirely then return, we must fire this
        as a history change event. Unfortunately, we have lost
        all references to listeners from earlier, because JavaScript
        clears out. */
/** private */ fireOnNewListener: null,

/** A variable that indicates whether this is the first time
        this page has been loaded. If you go to a web page, leave
        it for another one, and then return, the page's onload
        listener fires again. We need a way to differentiate
        between the first page load and subsequent ones.
        This variable works hand in hand with the pageLoaded
        variable we store into historyStorage.*/
/** private */ firstLoad: null,

/** A variable to handle an important edge case in Internet
        Explorer. In IE, if a user manually types an address into
        their browser's location bar, we must intercept this by
        continiously checking the location bar with an timer 
        interval. However, if we manually change the location
        bar ourselves programmatically, when using our hidden
        iframe, we need to ignore these changes. Unfortunately,
        these changes are not atomic, so we surround them with
        the variable 'ieAtomicLocationChange', that if true,
        means we are programmatically setting the location and
        should ignore this atomic chunked change. */
/** private */ ieAtomicLocationChange: null, 

/** Creates the DHTML history infrastructure. */
/** private */ create: function() {
        // get our initial location
	var initialHash = this.getCurrentLocation();
        
        // save this as our current location
	this.currentLocation = initialHash;
        
        // write out a hidden iframe for IE and
	// set the amount of time to wait between add() requests
	if (this.isInternetExplorer()) {
                document.write("<iframe style='border:3px; width: 1px; "
                                                        + "height: 1px; position: absolute; bottom: 0px; "
                                                        + "right: 0px; visibility: visible;' "
                                                        + "name='DhtmlHistoryFrame' id='DhtmlHistoryFrame' "
                                                        + "src='blank.html?" + initialHash + "'>"
                                                        + "</iframe>");
                // wait 400 milliseconds between history
		// updates on IE, versus 200 on Firefox
		this.WAIT_TIME = 400;
        }
        
        // add an unload listener for the page; this is
	// needed for Firefox 1.5+ because this browser caches all
	// dynamic updates to the page, which can break some of our 
	// logic related to testing whether this is the first instance
	// a page has loaded or whether it is being pulled from the cache
	var self = this;
        window.onunload = function() {
                self.firstLoad = null;
        };
        
        // determine if this is our first page load;
	// for Internet Explorer, we do this in 
	// this.iframeLoaded(), which is fired on
	// page load. We do it there because
	// we have no historyStorage at this point
	// in IE, which only exists after the page
	// is finished loading for that browser
	if (this.isInternetExplorer() == false) {
                if (historyStorage.hasKey("DhtmlHistory_pageLoaded") == false) {
                        this.ignoreLocationChange = true;
                        this.firstLoad = true;
                        historyStorage.put("DhtmlHistory_pageLoaded", true);
                }
                else {
                        // indicate that we want to pay attention
			// to this location change
			this.ignoreLocationChange = false;
                        // For browser's other than IE, fire
			// a history change event; on IE,
			// the event will be thrown automatically
			// when it's hidden iframe reloads
			// on page load.
			// Unfortunately, we don't have any 
			// listeners yet; indicate that we want
			// to fire an event when a listener
			// is added.
			this.fireOnNewListener = true;
                }
        }
        else { // Internet Explorer
		// the iframe will get loaded on page
		// load, and we want to ignore this fact
		this.ignoreLocationChange = true;
        }
        
        if (this.isInternetExplorer()) {
                        this.iframe = document.getElementById("DhtmlHistoryFrame");
        } 

        // other browsers can use a location handler that checks
	// at regular intervals as their primary mechanism;
	// we use it for Internet Explorer as well to handle
	// an important edge case; see checkLocation() for
	// details
	var self = this;
        var locationHandler = function() {
                self.checkLocation();
        };
        setInterval(locationHandler, 100);
},

/** Notify the listener of new history changes. */
/** private */ fireHistoryEvent: function(newHash) {
        // extract the value from our history storage for
	// this hash
	var historyData = historyStorage.get(newHash);

        // call our listener
	this.listener.call(null, newHash, historyData);
},

/** Sees if the browsers has changed location.  This is the primary history mechanism
        for Firefox. For Internet Explorer, we use this to handle an important edge case:
        if a user manually types in a new hash value into their Internet Explorer location
        bar and press enter, we want to intercept this and notify any history listener. */
/** private */ checkLocation: function() {
        // ignore any location changes that we made ourselves
	// for browsers other than Internet Explorer
	if (this.isInternetExplorer() == false
                && this.ignoreLocationChange == true) {
                this.ignoreLocationChange = false;
                return;
        }
        
        // if we are dealing with Internet Explorer
	// and we are in the middle of making a location
	// change from an iframe, ignore it
	if (this.isInternetExplorer() == false
                && this.ieAtomicLocationChange == true) {
                return;
        }
        
        // get hash location
	var hash = this.getCurrentLocation();
        
        // see if there has been a change
	if (hash == this.currentLocation)
                return;
                
        // on Internet Explorer, we need to intercept users manually
	// entering locations into the browser; we do this by comparing
	// the browsers location against the iframes location; if they
	// differ, we are dealing with a manual event and need to
	// place it inside our history, otherwise we can return
	this.ieAtomicLocationChange = true;
        
        if (this.isInternetExplorer()
                && this.getIFrameHash() != hash) {
                this.iframe.src = "blank.html?" + hash;
        }
        else if (this.isInternetExplorer()) {
                // the iframe is unchanged
		return;
        }
                
        // save this new location
	this.currentLocation = hash;
        
        this.ieAtomicLocationChange = false;
        
        // notify listeners of the change
	this.fireHistoryEvent(hash);
},  

/** Gets the current location of the hidden IFrames
        that is stored as history. For Internet Explorer. */
/** private */ getIFrameHash: function() {
        // get the new location
	var historyFrame = document.getElementById("DhtmlHistoryFrame");
        var doc = historyFrame.contentWindow.document;
        var hash = new String(doc.location.search);

        if (hash.length == 1 && hash.charAt(0) == "?")
                hash = "";
        else if (hash.length >= 2 && hash.charAt(0) == "?")
                hash = hash.substring(1); 
        
        
        return hash;
},		

/** Removes any leading hash that might be on a location. */
/** private */ removeHash: function(hashValue) {
        if (hashValue == null || hashValue == undefined)
                return null;
        else if (hashValue == "")
                return "";
        else if (hashValue.length == 1 && hashValue.charAt(0) == "#")
                return "";
        else if (hashValue.length > 1 && hashValue.charAt(0) == "#")
                return hashValue.substring(1);
        else
                return hashValue;	
},		

/** For IE, says when the hidden iframe has finished loading. */
/** private */ iframeLoaded: function(newLocation) {
        // ignore any location changes that we made ourselves
	if (this.ignoreLocationChange == true) {
                this.ignoreLocationChange = false;
                return;
        }
        
        // get the new location
	var hash = new String(newLocation.search);
        if (hash.length == 1 && hash.charAt(0) == "?")
                hash = "";
        else if (hash.length >= 2 && hash.charAt(0) == "?")
                hash = hash.substring(1);
        
        // move to this location in the browser location bar
	// if we are not dealing with a page load event
	if (this.pageLoadEvent != true) {
                window.location.hash = hash;
        }

        // notify listeners of the change
	this.fireHistoryEvent(hash);
},

/** Determines if this is Internet Explorer. */
/** private */ isInternetExplorer: function() {
        var userAgent = navigator.userAgent.toLowerCase();
        if (document.all && userAgent.indexOf('msie')!=-1) {
                return true;
        }
        else {
                return false;
        }
}
};












/** An object that uses a hidden form to store history state 
        across page loads. The chief mechanism for doing so is using
        the fact that browser's save the text in form data for the
        life of the browser and cache, which means the text is still
        there when the user navigates back to the page. See
        http://codinginparadise.org/weblog/2005/08/ajax-tutorial-saving-session-across.html
        for full details. */
window.historyStorage = {
/** If true, we are debugging and show the storage textfield. */
/** public */ debugging: false,

/** Our hash of key name/values. */
/** private */ storageHash: new Object(),

/** If true, we have loaded our hash table out of the storage form. */
/** private */ hashLoaded: false, 

/** public */ put: function(key, value) {
        this.assertValidKey(key);
        
        // if we already have a value for this,
	// remove the value before adding the
	// new one
	if (this.hasKey(key)) {
                this.remove(key);
        }
        
        // store this new key
	this.storageHash[key] = value;
        
        // save and serialize the hashtable into the form
	this.saveHashTable(); 
},

/** public */ get: function(key) {
        this.assertValidKey(key);
        
        // make sure the hash table has been loaded
	// from the form
	this.loadHashTable();
        
        var value = this.storageHash[key];

        if (value == undefined)
                return null;
        else
                return value; 
},

/** public */ remove: function(key) {
        this.assertValidKey(key);
        
        // make sure the hash table has been loaded
	// from the form
	this.loadHashTable();
        
        // delete the value
	delete this.storageHash[key];
        
        // serialize and save the hash table into the 
	// form
	this.saveHashTable();
},

/** Clears out all saved data. */
/** public */ reset: function() {
        this.storageField.value = "";
        this.storageHash = new Object();
},

/** public */ hasKey: function(key) {
        this.assertValidKey(key);
        
        // make sure the hash table has been loaded
	// from the form
	this.loadHashTable();
        
        if (typeof this.storageHash[key] == "undefined")
                return false;
        else
                return true;
},

/** Determines whether the key given is valid;
        keys can only have letters, numbers, the dash,
        underscore, spaces, or one of the 
        following characters:
        !@#$%^&*()+=:;,./?|\~{}[] */
/** public */ isValidKey: function(key) {
        // allow all strings, since we don't use XML serialization
	// format anymore
	return (typeof key == "string");
        
        /*
        if (typeof key != "string")
                key = key.toString();
        
        
        var matcher = 
                /^[a-zA-Z0-9_ \!\@\#\$\%\^\&\*\(\)\+\=\:\;\,\.\/\?\|\\\~\{\}\[\]]*$/;
                                        
        return matcher.test(key);*/
},




/** A reference to our textarea field. */
/** private */ storageField: null,

/** private */ init: function() {
        // write a hidden form into the page
	var styleValue = "position: absolute; top: -1000px; left: -1000px;";
        if (this.debugging == true) {
                styleValue = "width: 30em; height: 30em;";
        }
        
        var newContent =
                "<form id='historyStorageForm' " 
                        + "method='GET' "
                        + "style='" + styleValue + "'>"
                        + "<textarea id='historyStorageField' "
                                        + "style='" + styleValue + "'"
                                                        + "left: -1000px;' "
                                        + "name='historyStorageField'></textarea>"
                + "</form>";
        document.write(newContent);
        
        this.storageField = document.getElementById("historyStorageField");
},

/** Asserts that a key is valid, throwing
        an exception if it is not. */
/** private */ assertValidKey: function(key) {
        if (this.isValidKey(key) == false) {
                throw "Please provide a valid key for "
                        + "window.historyStorage, key= "
                        + key;
        }
},

/** Loads the hash table up from the form. */
/** private */ loadHashTable: function() {
        if (this.hashLoaded == false) {
                // get the hash table as a serialized
		// string
		var serializedHashTable = this.storageField.value;
                
                if (serializedHashTable != "" &&
                        serializedHashTable != null) {
                        // destringify the content back into a 
			// real JavaScript object
			this.storageHash = eval('(' + serializedHashTable + ')');  
                }
                
                this.hashLoaded = true;
        }
},

/** Saves the hash table into the form. */
/** private */ saveHashTable: function() {
        this.loadHashTable();
        
        // serialized the hash table
	var serializedHashTable = "";
        
        // save this value
	this.storageField.value = serializedHashTable;
}
};

/** Initialize all of our objects now. */
window.historyStorage.init();
window.dhtmlHistory.create();


	window.onload = initialize;
	function initialize() 
	{
		dhtmlHistory.initialize();
	
		dhtmlHistory.addListener(handleHistoryChange);
		
	   var currentLocation = dhtmlHistory.getCurrentLocation();
	  
	   	     
	   displayLocation(currentLocation, null);
		
	}
	
	function handleHistoryChange(newLocation, historyData) 
	{ 
	   displayLocation(newLocation, historyData);
	}


	function displayLocation(newLocation,sectionData) 
	{
		
	   var expohis;
		
	   expohis=	newLocation.split('@');
		if(document.getElementById(expohis[1]))
		{
		
			var selectedElement = document.getElementById(expohis[1]);
				
	
			if (sectionData == null && document.getElementById(expohis[1])) 
				sectionData = selectedElement.innerHTML;  
	
			selectedElement.innerHTML = sectionData;
			if(dhtmlhisfile[newLocation])
			printscript(expohis[1],dhtmlhisfile[newLocation]);
			
		}
	}