// JavaScript Document

function check_username(username)
{
	// Generating Ajax Object
	xmlHttp = GetXmlHttpObject()
	
	// if match criteria
	if (xmlHttp == null)
	{
		// Showing user message
		alert ("Your browser does not support AJAX!");
		return;
	}
	// Making Request Format  For cities
	var url="ajax/check_username.php?username="+username;
	
	//alert("url: "+ url)
	xmlHttp.onreadystatechange=stateChanged_username;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);	
}
	
/* Recieving Response  For dept list */
function stateChanged_username() 
{ 
	// if returned response is in ready state to give output
	if (xmlHttp.readyState==4)
		// Showing Output on template from returned responsed Text
		document.getElementById('username_field').innerHTML = xmlHttp.responseText;			
	else
		// Showing Pre-loader as Output on template before showing returned responsed Text
		document.getElementById('username_field').innerHTML='<img src="images/loader.gif"> &nbsp; &nbsp; &nbsp; <img src="images/loader.gif">&nbsp; &nbsp; &nbsp; <img src="images/loader.gif">';
	
}

	/*********************************************/
	// Function Body XML HTTP Object for Ajax
	/*********************************************/
	function GetXmlHttpObject()
	{
		var xmlHttp=null;
		try
		{
		  // Firefox, Opera 8.0+, Safari
		  xmlHttp=new XMLHttpRequest();
		}
		catch (e)
		{
		  // Internet Explorer
			try
			{
				xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
			}
			catch (e)
			{
				xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
			}
		}
		return xmlHttp;
	}