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.getElementById('guestbookfrm').security_code.value ="";
			document.getElementById('guestbookfrm').security_code.focus();
			return false;
		  } else {
			document.getElementById('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;
}