/* Simple AJAX Code-Kit (SACK) */

/* ©2005 Gregory Wild-Smith */

/* www.twilightuniverse.com */

/* Software licenced under a modified X11 licence, see documentation or authors website for more details */



function sack(file){

	this.AjaxFailedAlert = "Your browser does not support the enhanced functionality of this website, and therefore you will have an experience that differs from the intended one.\n";

	this.requestFile = file;

	this.method = "POST";

	this.URLString = "";

	this.encodeURIString = true;

	this.execute = false;



	this.onLoading = function() { };

	this.onLoaded = function() { };

	this.onInteractive = function() { };

	this.onCompletion = function() { };



	this.createAJAX = function() {

		try {

			this.xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");

		} catch (e) {

			try {

				this.xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

			} catch (err) {

				this.xmlhttp = null;

			}

		}

		if(!this.xmlhttp && typeof XMLHttpRequest != "undefined")

			this.xmlhttp = new XMLHttpRequest();

		if (!this.xmlhttp){

			this.failed = true; 

		}

	};

	

	this.setVar = function(name, value){

		if (this.URLString.length < 3){

			this.URLString = name + "=" + value;

		} else {

			this.URLString += "&" + name + "=" + value;

		}

	}

	

	this.encVar = function(name, value){

		var varString = encodeURIComponent(name) + "=" + encodeURIComponent(value);

	return varString;

	}

	

	this.encodeURLString = function(string){

		varArray = string.split('&');

		for (i = 0; i < varArray.length; i++){

			urlVars = varArray[i].split('=');

			if (urlVars[0].indexOf('amp;') != -1){

				urlVars[0] = urlVars[0].substring(4);

			}

			varArray[i] = this.encVar(urlVars[0],urlVars[1]);

		}

	return varArray.join('&');

	}

	

	this.runResponse = function(){

		eval(this.response);

	}

	

	this.runAJAX = function(urlstring){

		this.responseStatus = new Array(2);

		if(this.failed && this.AjaxFailedAlert){ 

			alert(this.AjaxFailedAlert); 

		} else {

			if (urlstring){ 

				if (this.URLString.length){

					this.URLString = this.URLString + "&" + urlstring; 

				} else {

					this.URLString = urlstring; 

				}

			}

			if (this.encodeURIString){

				var timeval = new Date().getTime(); 

				this.URLString = this.encodeURLString(this.URLString);

				this.setVar("rndval", timeval);

			}

			if (this.element) { this.elementObj = document.getElementById(this.element); }

			if (this.xmlhttp) {

				var self = this;

				if (this.method == "GET") {

					var totalurlstring = this.requestFile + "?" + this.URLString;

					this.xmlhttp.open(this.method, totalurlstring, true);

				} else {

					this.xmlhttp.open(this.method, this.requestFile, true);

				}

				if (this.method == "POST"){

  					try {

						this.xmlhttp.setRequestHeader('Content-Type','application/x-www-form-urlencoded')  

					} catch (e) {}

				}



				this.xmlhttp.send(this.URLString);

				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;

							self.responseStatus[0] = self.xmlhttp.status;

							self.responseStatus[1] = self.xmlhttp.statusText;

							self.onCompletion();

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

							if (self.elementObj) {

								var 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;

								}

							}

							self.URLString = "";

						break;

					}

				};

			}

		}

	};

this.createAJAX();

}