var timercount = 0;
function startTimer() {
  if(timercount<10)
    timercount='0'+timercount;
    
  setTimeout('startTimer()',1000);
  timercount++;
  document.getElementById('timer_cage').innerHTML = CAPTCHA_TIMEOUT - timercount;
  if(timercount == CAPTCHA_TIMEOUT) {
    timercount = 0;
    changeCaptchaImage();
   }
}
    
//Called every time when form is perfomed
function changeCaptchaImage() {   	
    if(window.location.protocol=="https:"){
        if(ajaxURL.substr(0,5) == "http:"){
            ajaxURL = "https" + ajaxURL.substr(4);
        }
    }
    var url = ajaxURL + 'captcha/image.php';      
    var getstr = '';        
    makeRequest(url, getstr);
}


// XmlHttpRequest object
var receiveReq = getXmlHttpRequestObject();

//initiate 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) {    
        //true sets the request to asyncronous(default)
        receiveReq.open("GET", url, true);
        //set function that will be called when the XmlHttpRequest objects state changes
        receiveReq.onreadystatechange = updatePage;
        receiveReq.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        receiveReq.setRequestHeader("Content-length", param.length);
        receiveReq.setRequestHeader("Connection", "close");
        receiveReq.send(param);
    }
}

//gets 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 {   
        alert("Your browser doesn't support the XmlHttpRequest object.");
    }
}
	
//Called every time  XmlHttpRequest objects state changes
function updatePage(){
	 //Check if our response is ready
	 if (receiveReq.readyState == 4) {
	   img = document.getElementById('captcha_image');
	   img.src =  ajaxURL + 'captcha/image.php?' + Math.random();
    }
}