//var request = null;
/* Initialize a Request object that is already constructed */

function initReq(reqType,url,bool,respHandle){
    try{
        /* Specify the function that will handle the HTTP response */
        request.onreadystatechange = respHandle;
        request.open( reqType ,url ,bool );
        //if the reqType parameter is POST, then the
        //5th argument to the function is the POSTed data
        if(reqType.toLowerCase() == "post") {
            request.setRequestHeader("Content-Type",
                        "application/x-www-form-urlencoded; charset=UTF-8");
            request.send(arguments[4]);
        }   else {
            request.send(null);
        }

    } catch (errv) {
        //alert(
        //        "The application cannot contact "+
        //        "the server at the moment. "+
        //        "Please try again in a few seconds.\n"+
        //        "Error detail: "+errv.message);
    }
}

/* Wrapper function for constructing a Request object.
 Parameters:
  reqType: The HTTP request type such as GET or POST.
  url: The URL of the server program.
  asynch: Whether to send the request asynchronously or not.
  respHandle: The name of the function that will handle the response.
  Any fifth parameters represented as arguments[4] are the data a
  POST request is designed to send. */
function httpRequest(reqType,url,asynch,respHandle){
    //Mozilla-based browsers
    if(window.XMLHttpRequest){
        request = new XMLHttpRequest();
    } else if (window.ActiveXObject){
        request = new ActiveXObject("Msxml2.XMLHTTP");
        if (! request){
            request = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    //Very unlikely, but we test for a null request
    //if neither ActiveXObject was initialized
    
    //alert( typeof request );
    
    if(request)  {
        //if the reqType parameter is POST, then the
        //5th argument to the function is the POSTed data
        if(reqType.toLowerCase() != "post") {
            initReq(reqType,url,asynch,respHandle);
        }  else {
            //the POSTed data
            var args = arguments[4];
            if(args != null && args.length > 0){
                initReq(reqType,url,asynch,respHandle,args);
            }
        }
    }  else {
        //alert("Your browser does not permit the use of all "+
        //      "of this application's features!");
    }
}