function GetXmlHttpObject() {
    var xmlHttp=null;
    try {
	// Firefox, Opera 8.0+, Safari
	xmlHttp=new XMLHttpRequest();
    } catch (e) {
	// Internet Explorer
	try {
	    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
	} catch (e) {
	    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
	}
    }
    return xmlHttp;
}