var xmlhttp
var goodun = 0;
var rchk = new Image(21,20);
rchk.src = 'graphics/red_check.png';
var gchk = new Image(21,20);
gchk.src = 'graphics/green_check.png';
function updateTable(str)
{
xmlresponse = 0;
xmlhttp=GetXmlHttpObject();
if (xmlhttp==null)
  {
  alert ("Your browser does not support XMLHTTP!");
  return;
  }
var url="reg_response.php";
if(str.length>1) { url=url+str; }
xmlhttp.onreadystatechange=stateChanged;
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
}

function stateChanged()
{
if (xmlhttp.readyState==4)
  {
  	var data = xmlhttp.responseText;
	if(data=='true') {
		goodun = 1;
		document.getElementById('checkimg').src = gchk.src;
	} else {
		goodun = 0;
		document.getElementById('checkimg').src = rchk.src;
		alert('That Username is already taken please choose another one');
	}
  }
}

function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  return new XMLHttpRequest();
  }
if (window.ActiveXObject)
  {
  // code for IE6, IE5
  return new ActiveXObject("Microsoft.XMLHTTP");
  }
return null;
}

function getNodeValue(obj,tag)
{
	return obj.getElementsByTagName(tag)[0].firstChild.nodeValue;
}