/* Simple AJAX Code-Kit (SACK) */
/* ?005 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 = _G(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();
}