function Inint_AJAX() {
   try { return new ActiveXObject("Msxml2.XMLHTTP");  } catch(e) {} //IE
   try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch(e) {} //IE
   try { return new XMLHttpRequest(); } catch(e) {} //Native Javascript
   alert("XMLHttpRequest not supported");
   return null;
};

function security_code(src) {
	 var req = Inint_AJAX();
     req.onreadystatechange = function () {
          if (req.readyState==4) {
               if (req.status==200) {
				  // alert(req.responseText);
                    document.getElementById(src).innerHTML=req.responseText; //ÃѺ¤èÒ¡ÅѺÁÒ
					
               }
          }
     };
	 
	code=document.getElementById("vcode").value;
     req.open("GET", "ajax.php?code="+code);
     req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded;charset=tis-620"); // set Header
    // alert(src+id);
	 req.send(null); //Ê觤èÒ
}