//Gets the browser specific XmlHttpRequest Object
	function getXmlHttpRequestObject() {
		if (window.XMLHttpRequest) {
			return new XMLHttpRequest(); //Mozilla, Safari ...
		} else if (window.ActiveXObject) {
			return new ActiveXObject("Microsoft.XMLHTTP"); //IE
		} else {
			//Display our error message
			alert("Your browser doesn't support the XmlHttpRequest object.");
		}
	}

	//Our XmlHttpRequest object
	var receiveReq = getXmlHttpRequestObject();

	//Initiate the AJAX request
	function makeRequest(url, param) {
	//If our readystate is either not started or finished, initiate a new request
		 if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
			//Set up the connection to captcha_test.html. True sets the request to asyncronous(default) 
			receiveReq.open("POST", url, true);
			
			//Set the function that will be called when the XmlHttpRequest objects state changes
			receiveReq.onreadystatechange = updatePage; 

			//Add HTTP headers to the request
			receiveReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
			receiveReq.setRequestHeader("Content-length", param.length);
			receiveReq.setRequestHeader("Connection", "close");

			//Make the request
			receiveReq.send(param);
		}
	}

	//Called every time our XmlHttpRequest objects state changes
	function updatePage() {
	 //Check if our response is ready
		if (receiveReq.readyState == 4) {
			//Set the content of the DIV element with the response text
			//document.getElementById('result').innerHTML = receiveReq.responseText;
		   
			if (receiveReq.responseText == 'wrong') {
				//Get a reference to CAPTCHA image
				img = document.getElementById('imgCaptcha'); 
				//Change the image
				img.src = 'captchaImage.php?' + Math.random();
				
				document.getElementById('txtCaptcha').className = 'hiba';
				
				
			} else {
				document.getElementById('contactframe').src = 'contact.php';
				document.contact.submit();
			}
		}
	}

	//Called every time when form is perfomed
	function getParam(theForm) {
		//Set the URL
		var url = 'captcha.php';
		//Set up the parameters of our AJAX call
		var postStr = theForm.txtCaptcha.name + "=" + encodeURIComponent( theForm.txtCaptcha.value );
		//Call the function that initiate the AJAX request
		makeRequest(url, postStr);
	}