/**
 * 
 * @param {String} HttpUrl - The Url to post to
 * @param {Object} CallBackContext - The object which contains the CallBackFunction
 * @param {Method} CallBackFunction - The call back function
 * @param {String} PostMethod - The get/post method
 * @param {String} Parameters - Parameters to pass in the get/post string
 * @param {Object} ContextHandler - This is an instance of our  global context handler. That allows concurrent ajax calls correctly.
 */
function Ajaxv2(HttpUrl,CallBackContext,CallBackFunction,PostMethod,Parameters,ContextHandler)
{	
	this.HttpUrl		= HttpUrl;
	this.PostMethod		= PostMethod;
	this.Parameters		= Parameters;
	this.ContextHandler	= ContextHandler;
	this.Handled		= false;	
	this.Version		= 2.0;
	this.Request		= null;
	this.EventData		= null;
	
	GlobalAjaxv2Context	= this; //really only for single fired events, 2 concurrent wont' work without a  context handler.
	
	if(typeof(ContextHandler) == "undefined")
		this.ContextHandler=null

	//this checks our state and performs the callback function on success
	this.GlobalProcessRequestAjaxv2 = function()
	{		
		
		//when this even fires, our context is WITHIN the XMLHttpRequest object itself
		if(typeof(ContextHandler) != "undefined")
		{
			/*
			 * DO NOT fire our event off our globallly stored context. we are using a Context Handler meaning we are firing 2+ events at once. We need
			 * to let the context handler do its thing.
			*/
			ContextHandler.CheckEvents();
		}			
		else
			GlobalAjaxv2Context.ProcessRequestAjaxv2();
	}
	this.ProcessRequestAjaxv2 = function()
     {	
	 	try
		{
			if(this.Request.readyState == 4) 
			{
				//According to the HTTP 1.1 specification, any response that has a code between 200 and 299 inclusive is a successful response.
				if(this.Request.status >= 200 && this.Request.status <= 299) 
				{
					CallBackFunction.call(CallBackContext,true,this.Request,this.EventData);					
				} 
				else 
				{
					//error out with the server error code and message.
					CallBackFunction.call(CallBackContext,false,this.Request,this.EventData);
				}
			}
		}
		catch(exception)
		{
			alert("An exception was caught while trying to process an AJAX request. ("+exception+")");
		}		        	
     }	
					
	//this creates our object
     this.InitAjaxv2 = function()
     {	     
	     try 
	     {
	     	HttpRequest = new XMLHttpRequest();
	     } 
	     catch(e) 
	     {
	     	try 
	       	{
	       		HttpRequest = new ActiveXObject("Msxml2.XMLHTTP");
	       	} 
	       	catch (e) 
	       	{
	        	try 
	        	{
	         		HttpRequest = new ActiveXObject("Microsoft.XMLHTTP");
	         	} 
	         	catch (E) 
	         	{
	          		HttpRequest = null;
	         	}
	       	}
	     }	     
	     return HttpRequest;
	 }
	

	//this actually sends the get or post request
	this.GetPost = function(Async)
	{
		this.Request = this.InitAjaxv2();

		if(this.Request == null)
			return false;
			
		this.Request.onreadystatechange=this.GlobalProcessRequestAjaxv2;
		
		//setup our context handler if we need to
		if(this.ContextHandler != null)
			this.ContextHandler.AddAjaxv2Object(this);
	
      	this.Request.open(this.PostMethod, this.HttpUrl, Async);
	    this.Request.setRequestHeader("Content-Type","application/x-www-form-urlencoded; charset=UTF-8");
	    this.Request.setRequestHeader("If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT");
      	this.Request.send(this.Parameters);
      	
      	/*
      		MOZ browser will never fire onreadystatechange when in synchronous mode,
      		but they will wait for req.send to complete. So we can fire the function here instead.
      		http://www.quirksmode.org/blog/archives/2005/09/xmlhttp_notes_r_2.html
      	*/
      	if (Async == false)      	
      	{
			this.GlobalProcessRequestAjaxv2();   	
      	}		
	}
	
	/*
	*   @name getFormValues()
	*   @descr This function creates a string of the name-value pairs for the specified form object
	*   @param (object) fobj - the form object that the values are wanted for
	*   @return str - the string containing the name-value pairs for the form object
	*/
	this.GetFormValues = function(fobj)
	{
	    var str = "";
	    var valueArr = null;
	    var val = "";
	    var cmd = "";
		var obj;
	
		//get all the inputs
		var objects = fobj.getElementsByTagName('input');
		for(var c = 0; c < objects.length; c++)
		{
			obj = objects[c];
			switch(obj.type)
			{
				case "text":				
				case "hidden":
				case "password":
					str += obj.id + "=" + encodeURIComponent(obj.value) + "&";				
					break;
					
				case "radio":				 
	                if  (obj.checked)
	                    str += obj.id + "=" + encodeURIComponent(obj.value) + "&";	                
	                break;	            
			}			
		}
		
		//since we can support a bunch of checkboxes with the same name, we need to store a list of values
		objects = fobj.getElementsByTagName('input');
		var checkbox_array=Array();
		for(var c = 0; c < objects.length; c++)
		{
			obj = objects[c];
			switch(obj.type)
			{
				case "checkbox":
				{
					if(obj.checked)
					{
						var found=0;
						//is this id already in the array, if so, add on ,value!
						for(var c2=0;c2<checkbox_array.length;c2++)
						{
							if(checkbox_array[c2].ID==obj.id)
							{
								found=1;
								checkbox_array[c2].Value+=","+encodeURIComponent(obj.value);
							}
						}
						if(!found)
							checkbox_array.push(new this.CheckboxHelper(obj.id,encodeURIComponent(obj.value)));
					}
					break;
				}
			}
		}
		//now loop through our checkbox_array and add to str
		for(var c=0;c<checkbox_array.length;c++)
		{
			obj=checkbox_array[c];
			str+=obj.ID+"="+obj.Value+"&";
		}
		
		objects = fobj.getElementsByTagName('select');
		for(var c = 0; c < objects.length; c++)
		{
			obj = objects[c];			
			switch(obj.type)
			{
				case "select-one":
					if(obj.selectedIndex >=0) //in FF, select with no options had an index of -1 ??					
	                	str += obj.id + "=" + encodeURIComponent(obj.options[obj.selectedIndex].value) + "&";
	                break;	            
	            
	            case "select-multiple":
	            	for(f=0;f<obj.length;f++)
					{
	                   	if(obj.options[f].selected==true)
	            			str += obj.id + "=" + encodeURIComponent(obj.options[f].value) + "&";       	 
	               	}
	            	break; 
			}
		}
		
		objects = fobj.getElementsByTagName('textarea');
		
		for(var c = 0; c < objects.length; c++)
		{
			obj = objects[c];	
			str += obj.id + "=" + encodeURIComponent(obj.value) + "&";
		}
	
		str = str.replace(/\+/g,"%2b"); //+ are going to spaces grr!	
	    str = str.substr(0,(str.length - 1));
	    return str;
	}
	
	this.CheckboxHelper=function(ID,Value)
	{
		this.ID		= ID;
		this.Value	= Value;
	}	
}