window.dhtmlHistory ={/** Initializes our DHTML history. You should
call this after the page is finished loading. */
 initialize:function(){// only Internet Explorer needs to be explicitly initialized;
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; 
}
},/** Adds a history change listener. Note that only 
one listener is supported at this time. */
 addListener:function(callback){this.listener = callback;
if (this.fireOnNewListener == true){this.fireHistoryEvent(this.currentLocation);
this.fireOnNewListener = false;
}
},/** public */ add:function(newLocation,historyData){// most browsers require that we wait a certain amount of time before changing the
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;
newLocation = self.removeHash(newLocation);
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; 
}
historyStorage.put(newLocation,historyData);
self.ignoreLocationChange = true;
this.ieAtomicLocationChange = true;
self.currentLocation = newLocation;
window.location.hash = newLocation;
if (self.isInternetExplorer())
self.iframe.src = "blank.php?" + newLocation;
this.ieAtomicLocationChange = false;
};
window.setTimeout(addImpl,this.currentWaitTime);
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. */
 getCurrentLocation:function(){var currentLocation = this.removeHash(window.location.hash);
return currentLocation;
},/** Our current hash location,without the "#" symbol. */
 currentLocation:null,/** Our history change listener. */
 listener:null,/** A hidden IFrame we use in Internet Explorer to detect history
changes. */
 iframe:null,/** Indicates to the browser whether to ignore location changes. */
 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. */
 WAIT_TIME:200,/** The amount of time in milliseconds an add request has to wait in line before being
run on a window.setTimeout. */
 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. */
 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.*/
 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. */
 ieAtomicLocationChange:null,/** Creates the DHTML history infrastructure. */
 create:function(){// get our initial location
var initialHash = this.getCurrentLocation();
this.currentLocation = initialHash;
if (this.isInternetExplorer()){document.write("<iframe style='border:0px; width:1px; "
+ "height:1px; position:absolute; bottom:0px; "
+ "right:0px; visibility:visible;' "
+ "name='DhtmlHistoryFrame' id='DhtmlHistoryFrame' "
+ "src='blank.php?" + initialHash + "'>"
+ "</iframe>");
this.WAIT_TIME = 400;
}
var self = this;
window.onunload = function(){self.firstLoad = null;
};
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
this.ignoreLocationChange = false;
this.fireOnNewListener = true;
}
}
else{// Internet Explorer
this.ignoreLocationChange = true;
}
if (this.isInternetExplorer()){this.iframe = document.getElementById("DhtmlHistoryFrame");
} 
var self = this;
var locationHandler = function(){self.checkLocation();
};
setInterval(locationHandler,100);
},/** Notify the listener of new history changes. */
 fireHistoryEvent:function(newHash){// extract the value from our history storage for this hash
var historyData = historyStorage.get(newHash);
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. */
 checkLocation:function(){// ignore any location changes that we made ourselves
if (this.isInternetExplorer() == false
&& this.ignoreLocationChange == true){this.ignoreLocationChange = false;
return;
}
if (this.isInternetExplorer() == false
&& this.ieAtomicLocationChange == true){return;
}
var hash = this.getCurrentLocation();
if (hash == this.currentLocation)
return;
this.ieAtomicLocationChange = true;
if (this.isInternetExplorer() && this.getIFrameHash() != hash){this.iframe.src = "blank.php?" + hash;
}
else if (this.isInternetExplorer()){// the iframe is unchanged
return;
}
this.currentLocation = hash;
this.ieAtomicLocationChange = false;
this.fireHistoryEvent(hash);
},/** Gets the current location of the hidden IFrames
that is stored as history. For Internet Explorer. */
 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. */
 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. */
 iframeLoaded:function(newLocation){// ignore any location changes that we made ourselves
if (this.ignoreLocationChange == true){this.ignoreLocationChange = false;
return;
}
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);
if (this.pageLoadEvent != true){window.location.hash = hash;
}
this.fireHistoryEvent(hash);
},/** Determines if this is Internet Explorer. */
 isInternetExplorer:function(){var userAgent = navigator.userAgent.toLowerCase();
if (document.all && userAgent.indexOf('msie')!=-1){return true;
}
else{return false;
}
}
};
window.historyStorage ={/** If true,we are debugging and show the storage textfield. */
 debugging:false,/** Our hash of key name/values. */
 storageHash:new Object(),/** If true,we have loaded our hash table out of the storage form. */
 hashLoaded:false,/** public */ put:function(key,value){this.assertValidKey(key);
if (this.hasKey(key)){this.remove(key);
}
this.storageHash[key] = value;
this.saveHashTable(); 
},/** public */ get:function(key){this.assertValidKey(key);
this.loadHashTable();
var value = this.storageHash[key];
if (value == undefined)
return null;
else
return value; 
},/** public */ remove:function(key){this.assertValidKey(key);
this.loadHashTable();
delete this.storageHash[key];
this.saveHashTable();
},/** Clears out all saved data. */
 reset:function(){this.storageField.value = "";
this.storageHash = new Object();
},/** public */ hasKey:function(key){this.assertValidKey(key);
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:!@#$%^&*()+=:;,./?|\~{}[] */
 isValidKey:function(key){// allow all strings,since we don't use XML serialization
return (typeof key == "string");
},/** A reference to our textarea field. */
 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. */
 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. */
 loadHashTable:function(){if (this.hashLoaded == false){// get the hash table as a serialized
var serializedHashTable = this.storageField.value;
if (serializedHashTable != "" &&
serializedHashTable != null){// destringify the content back into a 
this.storageHash = eval('(' + serializedHashTable + ')'); 
}
this.hashLoaded = true;
}
},/** Saves the hash table into the form. */
 saveHashTable:function(){this.loadHashTable();
var serializedHashTable = JSON.stringify(this.storageHash);
this.storageField.value = serializedHashTable;
} 
};
Array.prototype.______array = '______array';
var JSON ={org:'http://www.JSON.org',copyright:'(c)2005 JSON.org',license:'http://www.crockford.com/JSON/license.html',stringify:function (arg){var c,i,l,s = '',v;
switch (typeof arg){case 'object':if (arg){if (arg.______array == '______array'){for (i = 0; i < arg.length; ++i){v = this.stringify(arg[i]);
if (s){s += ',';
}
s += v;
}
return '[' + s + ']';
} else if (typeof arg.toString != 'undefined'){for (i in arg){v = arg[i];
if (typeof v != 'undefined' && typeof v != 'function'){v = this.stringify(v);
if (s){s += ',';
}
s += this.stringify(i) + ':' + v;
}
}
return '{' + s + '}';
}
}
return 'null';
case 'number':return isFinite(arg) ? String(arg):'null';
case 'string':l = arg.length;
s = '"';
for (i = 0; i < l; i += 1){c = arg.charAt(i);
if (c >= ' '){if (c == '\\' || c == '"'){s += '\\';
}
s += c;
} else{switch (c){case '\b':s += '\\b';
break;
case '\f':s += '\\f';
break;
case '\n':s += '\\n';
break;
case '\r':s += '\\r';
break;
case '\t':s += '\\t';
break;
default:c = c.charCodeAt();
s += '\\u00' + Math.floor(c / 16).toString(16) +
(c % 16).toString(16);
}
}
}
return s + '"';
case 'boolean':return String(arg);
default:return 'null';
}
},parse:function (text){var at = 0;
var ch = ' ';
function error(m){throw{name:'JSONError',message:m,at:at - 1,text:text
};
}
function next(){ch = text.charAt(at);
at += 1;
return ch;
}
function white(){while (ch != '' && ch <= ' '){next();
}
}
function str(){var i,s = '',t,u;
if (ch == '"'){outer:while (next()){if (ch == '"'){next();
return s;
} else if (ch == '\\'){switch (next()){case 'b':s += '\b';
break;
case 'f':s += '\f';
break;
case 'n':s += '\n';
break;
case 'r':s += '\r';
break;
case 't':s += '\t';
break;
case 'u':u = 0;
for (i = 0; i < 4; i += 1){t = parseInt(next(),16);
if (!isFinite(t)){break outer;
}
u = u * 16 + t;
}
s += String.fromCharCode(u);
break;
default:s += ch;
}
} else{s += ch;
}
}
}
error("Bad string");
}
function arr(){var a = [];
if (ch == '['){next();
white();
if (ch == ']'){next();
return a;
}
while (ch){a.push(val());
white();
if (ch == ']'){next();
return a;
} else if (ch != ','){break;
}
next();
white();
}
}
error("Bad array");
}
function obj(){var k,o ={};
if (ch == '{'){next();
white();
if (ch == '}'){next();
return o;
}
while (ch){k = str();
white();
if (ch != ':'){break;
}
next();
o[k] = val();
white();
if (ch == '}'){next();
return o;
} else if (ch != ','){break;
}
next();
white();
}
}
error("Bad object");
}
function num(){var n = '',v;
if (ch == '-'){n = '-';
next();
}
while (ch >= '0' && ch <= '9'){n += ch;
next();
}
if (ch == '.'){n += '.';
while (next() && ch >= '0' && ch <= '9'){n += ch;
}
}
if (ch == 'e' || ch == 'E'){n += 'e';
next();
if (ch == '-' || ch == '+'){n += ch;
next();
}
while (ch >= '0' && ch <= '9'){n += ch;
next();
}
}
v = +n;
if (!isFinite(v)){error("Bad number");
} else{return v;
}
}
function word(){switch (ch){case 't':if (next() == 'r' && next() == 'u' && next() == 'e'){next();
return true;
}
break;
case 'f':if (next() == 'a' && next() == 'l' && next() == 's' &&
next() == 'e'){next();
return false;
}
break;
case 'n':if (next() == 'u' && next() == 'l' && next() == 'l'){next();
return null;
}
break;
}
error("Syntax error");
}
function val(){white();
switch (ch){case '{':return obj();
case '[':return arr();
case '"':return str();
case '-':return num();
default:return ch >= '0' && ch <= '9' ? num():word();
}
}
return val();
}
};
window.historyStorage.init();
window.dhtmlHistory.create();