var http = false;

if(navigator.appName == "Microsoft Internet Explorer") {
  http = new ActiveXObject("Microsoft.XMLHTTP");
} else {
  http = new XMLHttpRequest();
}

function validate(validation_code) {
	//alert('hiiiiii');
  http.abort();
  http.open("GET", "captcha.php?validation_code=" + validation_code, true);
  http.onreadystatechange=function() {
	  
    if(http.readyState == 4) {
		//alert(http.responseText);
		if(http.responseText=="Validation string not valid! ")
		{
		document.getElementById("proceed").disabled=true;   
  		 }
  		 else  if(http.responseText=="")
   		{
			document.getElementById("proceed").disabled=false;      
   		}	
      document.getElementById('result').innerHTML = http.responseText;
    }
  }
  http.send(null);
}