/* 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();
}