var request = false;
try
{
    request = new XMLHttpRequest();
}
catch (trymicrosoft)
{
    try
    {
        request = new ActiveXObject('Msxml2.XMLHTTP');
    }
    catch (othermicrosoft)
    {
        try
        {
            request = new ActiveXObject('Microsoft.XMLHTTP');
        }
        catch (failed)
        {
            request = false;
        }
    }
}
if (!request) alert ('Error initializing XMLHttpRequest!');

function connectByURL (url)
{
    request.open ('GET', url, true);
    request.onreadystatechange = getResponse;
    request.send(null);
}

function connectByURL2 (url)
{
    request.open ('GET', url, true);
    request.onreadystatechange = getResponse2;
    request.send(null);
}

function connectByURLpost (url, poststr)
{
    if (! url || ! poststr) return;
    request.open ('POST', url, true);
    request.onreadystatechange = getResponse;
    request.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
    request.setRequestHeader('Content-length', poststr.length);
    request.setRequestHeader('Connection', 'close');
    request.send(poststr);
}