var _httpRequest = false;
function makeHttpRequest(method, url, parameters)
{
    if (!_httpRequest)
    {
        if (window.XMLHttpRequest) // Mozilla, Safari,...
        { 
            _httpRequest = new window.XMLHttpRequest;
            
            if (_httpRequest.overrideMimeType)
                _httpRequest.overrideMimeType("text/plain");
        }
        else if (window.ActiveXObject) // IE
        {
            try
            {
                _httpRequest = new ActiveXObject("MSXML2.XMLHTTP.3.0");
            }
            catch (e)
            {
                try
                {
                    _httpRequest = new ActiveXObject("MSXML.XMLHTTP");
                }
                catch (e)
                {}
            }
        }
    }
    
    if (!_httpRequest)
    {
        if (document.images)
        {
            var img = new Image()
            img.src = url + parameters;
        }
        return false;
    }

    _httpRequest.onreadystatechange = getHttpResponse;
    _httpRequest.open("GET", url + parameters, true);                  
    _httpRequest.send(null);
}

function getHttpResponse()
{
    if (_httpRequest.readyState == 4)
    {
        if (_httpRequest.status == 200)
        {
            var result = _httpRequest.responseText;
            processHttpResponse(result);
        }
        else
        {
            errorHttpResponse();
        }
    }
}