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

    return req;
}

function getRequest(url,i,handler,requestArray)
{
    requestArray[i] = getRequestObject();

    if (requestArray[i] != null)
    {
        requestArray[i].open("GET",url,true);
        requestArray[i].onreadystatechange = handler;
        requestArray[i].send(null);
    }
}