function ajaxFunction(){
	var ajaxRequest;  // The variable that makes Ajax possible!

	try{
		// Opera 8.0+, Firefox, Safari
		ajaxRequest = new XMLHttpRequest();
	} catch (e){
		// Internet Explorer Browsers
		try{
			ajaxRequest = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			try{
				ajaxRequest = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e){
				// Something went wrong
				alert("Your browser broke!");
				return false;
			}
		}
	}
	// Create a function that will receive data sent from the server
	ajaxRequest.onreadystatechange = function()
  {
		if(ajaxRequest.readyState == 4){
		//var ajaxDisplay=document.myform.submit.value;
			var ajaxDisplay = document.getElementById('captchaImage');
			
			ajaxDisplay.src = 'captcha.php?' + Math.random();
;
	
		}
	}

	//var add = document.getElementById('$a').value;
//	alert("dd");

	ajaxRequest.open("GET", "captcha.php", true);
	
	ajaxRequest.send(null); 
}