var xmlhttp;
function validateCapcha(str)
{
//	alert(str);
if (str.length==0)
  {
	return false;
  }
xmlhttp=GetXmlHttpObject()
if (xmlhttp==null)
  {
  alert ("Your browser does not support XML HTTP Request");
  return;
  }
var url="validatecapcha.php";
url=url+"?security_code="+str;
url=url+"&sid="+Math.random();
//alert(url);
xmlhttp.onreadystatechange=stateChanged ;
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
}

function stateChanged()
{
if (xmlhttp.readyState==4)
  {
//	alert(xmlhttp.responseText);
//	Form = document.guestbookfrm;
	if(xmlhttp.responseText == "fail") {
		alert("Invalid Security Code");
		document.guestbookfrm.security_code.value = "";
		document.guestbookfrm.security_code.focus();
		return false;
	  } else {
		document.guestbookfrm.submit();  
	  }
  }
}

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;
}