var isIE = false;
function AJAX(file)
{
	/*
	* The XMLHttp object
	*/
	this.xmlhttp = null;

	/*
	* Reset all the properties
	*/
	this.resetData = function() {
		this.method = "POST";
  		this.queryStringSeparator = "?";
		this.argumentSeparator = "&";
		this.URLString = "";
		this.encodeURIString = true;
  		this.execute = false;
  		this.element = null;
		this.elementObj = null;
		this.requestFile = file;
		this.vars = new Object();
		this.responseStatus = new Array(2);
		this.response = "";
		this.responseXML = null;
		this.xmlDoc = null;
		this.encoding = "";
  	};

  	/*
  	* Reset all the methods
  	*/
	this.resetMethods = function() {
  		this.onLoading = function() { };
  		this.onLoaded = function() { };
  		this.onInteractive = function() { };
  		this.onCompletion = function() { };
  		this.onError = function() { };
		this.onFail = function() { };
	};

	/* Set aditional headers */
	this.setRequestHeader = function (header, value) {
		try {
			//alert("Setting header '" + header + ": " + value + "'");
			this.xmlhttp.setRequestHeader(header, value);
		} catch (e) { alert("Error setting request header '" + header + ": " + value + "'"); }
	}

	/*
	* Reset all properties and methods
	*/
	this.reset = function() {
		this.resetMethods();
		this.resetData();
	};

	/*
	* Create the XML Document object
	*/
	this.createXmlDoc = function () {
		if(isIE)
		{
			/* For Internet Explorer */
			this.xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
			this.xmlDoc.loadXML(this.response);
		}
		else
		{
			if(this.responseXML.documentElement)
			{
				this.xmlDoc = this.responseXML.documentElement;
			}
		}
	}

	/*
	* Create the XMLHTTP object
	*/
	this.createAJAX = function() {
		try {
			this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
			isIE = true;
		} catch (e1) {
			try {
				this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
				isIE = true;
			} catch (e2) {
				this.xmlhttp = null;
			}
		}

		if (! this.xmlhttp) {
			if (typeof XMLHttpRequest != "undefined") {
				this.xmlhttp = new XMLHttpRequest();
				if (this.xmlhttp.overrideMimeType) {
					if(this.encoding != "")
					{
						this.xmlhttp.overrideMimeType('text/xml; ' + this.encoding);
					}
					else
					{
						this.xmlhttp.overrideMimeType('text/xml');
					}
				}
			} else {
				this.failed = true;
			}
		}
	};

	/*
	* Set a variable
	*/
	this.setVar = function(name, value){
		this.vars[name] = Array(value, false);
	};

	/*
	* Encode a variable
	*/
	this.encVar = function(name, value, returnvars) {
		if (true == returnvars) {
			return Array(encodeURIComponent(name), encodeURIComponent(value));
		} else {
			this.vars[encodeURIComponent(name)] = Array(encodeURIComponent(value), true);
		}
	}

	/*
	* Parse the URL String
	*/
	this.processURLString = function(string, encode) {
		encoded = encodeURIComponent(this.argumentSeparator);
		regexp = new RegExp(this.argumentSeparator + "|" + encoded);
		varArray = string.split(regexp);
		for (i = 0; i < varArray.length; i++){
			urlVars = varArray[i].split("=");
			if (true == encode){
				this.encVar(urlVars[0], urlVars[1]);
			} else {
				this.setVar(urlVars[0], urlVars[1]);
			}
		}
	}

	/*
	* Create the URL String
	*/
	this.createURLString = function(urlstring) {
		if (this.encodeURIString && this.URLString.length) {
			this.processURLString(this.URLString, true);
		}

		if (urlstring) {
			if (this.URLString.length) {
				this.URLString += this.argumentSeparator + urlstring;
			} else {
				this.URLString = urlstring;
			}
		}

		// prevents caching of URLString
		this.setVar("rndval", new Date().getTime());

		urlstringtemp = new Array();
		for (key in this.vars) {
			if (false == this.vars[key][1] && true == this.encodeURIString) {
				encoded = this.encVar(key, this.vars[key][0], true);
				delete this.vars[key];
				this.vars[encoded[0]] = Array(encoded[1], true);
				key = encoded[0];
			}

			urlstringtemp[urlstringtemp.length] = key + "=" + this.vars[key][0];
		}
		if (urlstring){
			this.URLString += this.argumentSeparator + urlstringtemp.join(this.argumentSeparator);
		} else {
			this.URLString += urlstringtemp.join(this.argumentSeparator);
		}
	}

	/*
	* Run the response
	*/
	this.runResponse = function() {
		eval(this.response);
	}

	/*
	* Run AJAX
	*/
	this.runAJAX = function(urlstring) {
		if (this.failed) {
			this.onFail();
		} else {
			this.createURLString(urlstring);
			if (this.element) {
				this.elementObj = document.getElementById(this.element);
			}
			if (this.xmlhttp) {
				var self = this;
				if (this.method == "GET") {
					totalurlstring = this.requestFile + this.queryStringSeparator + this.URLString;
					this.xmlhttp.open(this.method, totalurlstring, true);
				} else {
					this.xmlhttp.open(this.method, this.requestFile, true);
					try {
						this.xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded")
					} catch (e) { }
				}

				this.xmlhttp.onreadystatechange = function() {
					switch (self.xmlhttp.readyState) {
						case 1:
							self.onLoading();
							break;
						case 2:
							self.onLoaded();
							break;
						case 3:
							self.onInteractive();
							break;
						case 4:
							self.response = self.xmlhttp.responseText;
							self.responseXML = self.xmlhttp.responseXML;
							try {
								self.responseStatus[0] = self.xmlhttp.status;
								self.responseStatus[1] = self.xmlhttp.statusText;
								self.createXmlDoc();

								if (self.execute) {
									self.runResponse();
								}

								if (self.elementObj) {
									elemNodeName = self.elementObj.nodeName;
									elemNodeName.toLowerCase();
									if (elemNodeName == "input"
									|| elemNodeName == "select"
									|| elemNodeName == "option"
									|| elemNodeName == "textarea") {
										self.elementObj.value = self.response;
									} else {
										self.elementObj.innerHTML = self.response;
									}
								}
								if (self.responseStatus[0] == "200") {
									self.onCompletion();
								} else {
									self.onError();
								}
							} catch (e) {}

							self.URLString = "";
							break;
					}
				};

				this.xmlhttp.send(this.URLString);
			}
		}
	};

	this.reset();
	this.createAJAX();
}