// JavaScript Document

function CheckCaptcha(prefix,top_dir)
{
  var str = document.getElementById(prefix+"_code").value; 
  var value = document.getElementById(prefix+"_value").value;
  //alert("CheckCaptcha:  code="+str+", value="+value);
  if (str == value) {
    document.getElementById(prefix+"_code").value = "";
    return true; }
  document.getElementById(prefix+"_image").src = top_dir+"captcha/blankcaptcha.jpg";
  //alert("Please enter a correct security code!");
  ajaxCaptchaGetNew(prefix,top_dir);
  return false; 
}


function ajaxCaptchaGetNew(prefix,top_dir)
{
  var xmlHttp = ajaxCaptchaGetXmlHttpObject();
  xmlHttp.onreadystatechange = function() { ajaxCaptchaGetNewHandler(xmlHttp,prefix,top_dir); }
  xmlHttp.open("GET",top_dir+"captcha/getnewcaptcha.php",true);
  xmlHttp.send(null);
}


function ajaxCaptchaGetNewHandler(xmlHttp,prefix,top_dir)
{
  if(xmlHttp.readyState!=4)
    return;
  try {
    var resp = xmlHttp.responseText;
    var i1 = resp.indexOf("(#")+2;
    var i2 = resp.indexOf("#)");							  
    var seccode = resp.substr(i1,i2-i1);
    document.getElementById(prefix+"_code").value = "";
    document.getElementById(prefix+"_image").src = top_dir+"temp/captcha"+seccode+".jpg";
    document.getElementById(prefix+"_value").value = seccode;
    var x = document.getElementById(prefix+"_value"); }
  catch(e) {
    alert("ajaxCaptchaGetNewHandler failed: "+e.message); }
}

function ajaxCaptchaGetXmlHttpObject()
{
var xmlHttp=null;
try {
  // Firefox, Opera 8.0+, Safari
  xmlHttp=new XMLHttpRequest(); }
catch (e)  {
  // Internet Explorer
  try {
    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP"); }
  catch (e) {
    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); } }
if (xmlHttp==null) {
  alert ("Your browser does not support AJAX!"); }   
return xmlHttp; 
}