function httpAjaxRequest()
{
	this.id =0;
	this.httpAjax   = null;
	this.sendParam  = null;
	this.charset    = 'UTF-8'; 
	this.Data       = null;  // data to send
	this._iframe    = null;
	this.timeout    = 10000;
	this.onreadystatechange = null;
	return this._init();
}

( function() 
{
id    = 0;        // transaction id
STACK = Array();  // array to store all transactions results

// Creates request object to server 
httpAjaxRequest.prototype.open = function(method,url,async,user,passwd)
{
	this.sendParam = 
	{
		'method' :  method,
		'url'    :  url,
		'async'  :  async,
		'user'   :  user,
		'passwd' :  passwd
	};
}


// Sends a request to server 
httpAjaxRequest.prototype.send = function()
{
	if(!this.httpAjax)
	{
		try     
		{
			this._init();
		}
		catch(e)
		{
			return false;
		}
	}
	
	// sending through XmlHTTP 
	if(this.httpAjax)
	{
		this._sendXmlHTTP(query);
	}
	
	// sending through Iframe object 
	else if(this._iframe)
	{
		try
		{
			//  sending via GET method    
			if(this.sendParam['method']=="GET")
			{
				var query = this.Data.type == 'form' ? this._formToString() : this._hashToString();
				this._iframe.src = this._addToUrl(query);                    
			}
			// sending via POST method        
			else
			{
				if(this.Data.type == 'form')
				{ 
					try
					{
						var newForm = this._iframe.document.createElement("input");
						// var newForm = doc.createElement(this.Data.value);
						// setTimeout(function(){this._iframe.contentWindow.document.body.appendChild(newForm)}, 0);               
					}
					catch(e)
					{
						alert(e.message);
					}
					// alert(this.iframe.forms[0].elements.length);
				} 
			}    
		}
		catch(e)
		{
			return false;
		}
	}  

}

// Obtains server answer
httpAjaxRequest.prototype.onreadystatechange2 = function()
{
	if(this.httpAjax)
	{  
		var _this = this; 
		tout = window.setInterval(
		function()
		{
			if(_this.httpAjax.readyState == 4)
			{
				_this._connAbort(tout);
			}
		}, 
		1); 
		setTimeout(function(){_this._connAbort(tout)},_this.timeout);  
	}
	else if(this._iframe){} 
}


httpAjaxRequest.prototype.getData = function()
{
 var _this = this; 
 tout = window.setInterval
 (
	function()
	{
		if(_this.httpAjax)
		{ 
			if(_this.httpAjax.readyState == 4)
			{
				return _this._connAbort(tout);
			}
		} 
		else if(this._iframe)
		{
			if(this._iframe.document.body.innerHTML!="")
			{
				if(iframe.document.body.load = true)
				{
					return _this._connAbort(tout);
				}
			}
		} 	
	},10
	); 
  setTimeout(function(){ return _this._connAbort(tout)},_this.timeout);  
}


// Aborts connection and clears timeout
httpAjaxRequest.prototype._connAbort = function(tout)
{
	window.clearInterval(tout); 
	if(this.httpAjax)
	{ 
		STACK[id] = {}; 
		STACK[id].httpStatus = this.httpAjax.status;
		if(this.httpAjax.status>=200&&this.httpAjax.status<300)
		{ 
			if(this.httpAjax.responseText)
			{
				STACK[id].responseText = this.httpAjax.responseText;
			}
			if(this.httpAjax.responseXML)
			{
				this._processXML(this.httpAjax.responseXML);
			}
		}
		else
		{
			STACK[id].responseText = null;
			STACK[id].responseXML  = null;
			switch(this.httpAjax.status)
			{
				case(400): STACK[id].httpResponse = "BAD REQUEST";          break;
				case(401): STACK[id].httpResponse = "NOT AUTHORIZED";       break;
				case(403): STACK[id].httpResponse = "ACCESS FORBIDDEN";     break;
				case(404): STACK[id].httpResponse = "DOCUMENT NOT FOUND";   break;
				case(408): STACK[id].httpResponse = "REQUEST TIMEOUT";      break;
				case(414): STACK[id].httpResponse = "REQUEST-URI TOO LONG"; break;
				case(502): STACK[id].httpResponse = "BAD GATEWAY";          break;
				case(503): STACK[id].httpResponse = "SERVICE UNAVAILABLE";  break;
				case(504): STACK[id].httpResponse = "GATEWAY TIMEOUT";      break;
			}
		}
	} 
	try{ this.onreadystatechange = this.onreadystatechange();}
	catch(e){}   
}

httpAjaxRequest.prototype.getResult = function()
{
	return STACK[id];
}

httpAjaxRequest.prototype._processXML = function(xmldata)
{
	for(var i = 0; i < xmldata.childNodes.length; i++)
	{ 
		if(xmldata.childNodes[i].nodeType == 1)
		{
			this._processXML(xmldata.childNodes[i]);
		}
		else 
		{
			STACK[id][xmldata.nodeName] = xmldata.childNodes[i].nodeValue;
		}
	}
}

// Method handles data from a form
httpAjaxRequest.prototype.prepareForm = function(formid)
{
	if(typeof formid == 'string')
	{
		var f = (document.getElementById(formid) || document.forms[formid]);
	}
	else if(typeof formid == 'object')
	{
		var f = formid;
	}
	else
	{
		 return; 
	}
	this.Data = {'type' : 'form', 'value' : f};
}

// Method handles data from hash object
httpAjaxRequest.prototype.prepareHash = function(hash)
{
	if(typeof hash == 'object')
	{
		this.Data ={'type' : 'hash', 'value' : hash};
	}
} 



// Private methods

// Initializes new XMLHttpRequest object
httpAjaxRequest.prototype._init = function()
{
	// microsoft ie browser - first way  //
	try
	{
		this.httpAjax = new ActiveXObject("Msxml2.XMLHTTP");
		return true;
	} 
	catch(e)
	{
		// microsoft ie browser - alternative way //
		try
		{
			this.httpAjax = new ActiveXObject("Microsoft.XMLHTTP");
			return true;
		}
		catch(e)
		{
			// non-microsoft browser  
			try
			{ 
				this.httpAjax = new XMLHttpRequest();
				return true;
			}
			catch(e)
			{
				// emulating XMLHttpRequest by iframe //
				/*
				try{
				this._iframe = document.createElement("IFRAME");
				this._iframe.style.width   = "400";
				this._iframe.style.height  = "400";
				this._iframe.style.border  = "2px solid #000";
				iframe.style.display = 'none';
				this._iframe.document = this._iframe.contentWindow.document?this._iframe.contentWindow.document:this._iframe.document;
				document.body.appendChild(this._iframe); 
				return true;
				}
				catch(e)
				{
				alert("Your browser does not support Ajax");    
				return false;  
				}
				*/
				return false;            
			} 
		}         
	}
}

// Sends data through XmlHTTP
httpAjaxRequest.prototype._sendXmlHTTP = function()
{
  var data = this.Data.type == 'form' ? this._formToString() : this._hashToString();
  // sending via GET method 
  if(this.sendParam['method'] == "GET")
   {
     var url = this._addToUrl(data);
     this.httpAjax.open(this.sendParam['method'],url, this.sendParam['async'], this.sendParam['user'],this.sendParam['passwd']);   
     this.httpAjax.send(null); 
   }
  // sending via POST method 
  else
    {
     
       this.httpAjax.open(this.sendParam['method'],this.sendParam['url'], this.sendParam['async'], this.sendParam['user'],this.sendParam['passwd']);
       this.httpAjax.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset='+this.charset);
       this.httpAjax.send(data);
    }  

}

httpAjaxRequest.prototype._sendIframe = function(data,charset)
{
}

// Adds data to url for GET method
httpAjaxRequest.prototype._addToUrl = function(data)
{
	return this.sendParam.url + (this.sendParam.url.indexOf('?') >= 0 ? '&' : '?') + data; 
}

// Converts a hash to valid request query
httpAjaxRequest.prototype._hashToString = function()
{
	var parts = [];
	var data = this.Data.value;
	for(var i in data)
	{
		parts[parts.length] = i + "=" + escape(data[i]);  
	}
	return parts.join('&'); 
}

// Converts form data to valid request query
httpAjaxRequest.prototype._formToString = function()
{
	var parts = [];
	var f = this.Data.value;
	for(i = 0; i < f.elements.length; i++)
	{   
		if(f.elements[i].name != "")
		parts[parts.length] = f.elements[i].name + "=" + escape(f.elements[i].value);
	}

	return parts.join('&'); 
}

})();