/* 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 = "Trình duyệt của bạn không hỗ trợ Load Ajax. Bạn nên chọn một trình duyệt khác để sử dụng được tất cả chức năng của hệ thống.\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();
}