// JavaScript Document

var request;
function validusrnam(cvalue)
{

if(document.frmsignup.txtusrnam.value=="")	
{
  document.getElementById('divusrnam').innerHTML="Username Should Not Be Left Blank";
  document.getElementById('txtusrnam').value="";
  document.frmsignup.txtusrnam.focus();
  return false;	
}

else if(document.frmsignup.txtusrnam.value!="")
{
    
	    
		   request=checkbrowser();
			if(request==null)
			{
				alert("please check Your Browser");
				return;
			}
		
		 url="chkusername.php?usrnam="+cvalue+"&mth="+Math.random();
		 request.onreadystatechange=checkemail;	
		  request.open("GET",url,true);
		  request.send(null);
}

function checkemail()
{
var echeck;
if(request.readyState==4)
	{
		var resp=request.responseText;
		if(resp==0)
		{
		document.getElementById('divusrnam').innerHTML="This Username already exists,Choose another";
		document.getElementById('txtusrnam').value="";
	    document.getElementById('txtusrnam').focus();			
		}
		else if(resp==1)
		{
		document.getElementById('divusrnam').innerHTML="<font color='green'>this username is available</font>";
		}
 	
	}	
}

// function for checking the browser compatibility of the code
function checkbrowser()
{
var request;

try
{
request=new XMLHttpRequest();
}
catch (e)
  {
	   try
		{
		request=new ActiveXObject("Msxml2.XMLHTTP");
		}
	  catch (e)
		{
			try
			  {
			  request=new ActiveXObject("Microsoft.XMLHTTP");
			  }
			catch (e)
				  {
				  alert("Your browser does not support AJAX!");
				  return false;
				  }
		}
  }
  return request;
}
}