function AjaxInit(){
    //Mozilla-based browsers
    if(window.XMLHttpRequest){
        request = new XMLHttpRequest();
    } else if (window.ActiveXObject){
        request=new ActiveXObject("Microsoft.XMLHTTP");
        if (! request){
            request=new ActiveXObject("Msxml2.XMLHTTP");
        }
    }    
    if(request){
        return request;
    }
    else{
        alert();
    }
}

function AjaxSend(url, id){     
  request = AjaxInit('Unable to comunicate with server !!! Ajax request is invalid');
	   
  request.onreadystatechange=function(){
    if(request.readyState == 4){
      if(request.status == 200){
        document.getElementById(id).innerHTML = request.responseText;   
      } else {
        alert('Unable to send request !!! Ajax failed !!! Stauts : '+ request.status);
        }
      }
    }; 
	   request.open('GET', url, true);
	   request.setRequestHeader( "If-Modified-Since", "Sat, 1 Jan 2000 00:00:00 GMT" );
	   request.send(null);
}