/// <reference name="MicrosoftAjax.js"/>
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
    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!");
    }
}