//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);
   //teceiveReq.setRequestHeader("Connection", "close");

     receiveReq.open("post", url+"?"+param);
     receiveReq.send(null);
     
   //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
   if(receiveReq.responseText == "1") {
   	//document.contact_form.form_state.value = 1;
   //submit_form(1);
   document.contact_form.submit();
   
  } else {
   document.getElementById('result').innerHTML = "<div id='error_box'>"+receiveReq.responseText+"</div>";
   //Get a reference to CAPTCHA image
   img = document.getElementById('imgCaptcha'); 
   //Change the image
   img.src = 'create_image.php?' + Math.random();
  }
 }
}

//Called every time when form is perfomed
function getParam(theForm) {
 //Set the URL
 var url = 'captcha.php';
 q = "";
 //Set up the parameters of our AJAX call
  for(i=0; i<theForm.elements.length; i++){
   q = q+"&"+theForm.elements[i].name+"="+theForm.elements[i].value;
  }
 var postStr = theForm.txtCaptcha.name + "=" + encodeURIComponent( theForm.txtCaptcha.value )+q;
 //Call the function that initiate the AJAX request
 makeRequest(url, postStr);
}