function createRequestObject() {
    var xmlhttp;
		try {
			xmlhttp = new XMLHttpRequest();
		} catch (e) {
			var MSXML_XMLHTTP_PROGIDS = new Array(
      		  'MSXML2.XMLHTTP.5.0',
			  'MSXML2.XMLHTTP.4.0',
			  'MSXML2.XMLHTTP.3.0',
			  'MSXML2.XMLHTTP',
			  'Microsoft.XMLHTTP');
			var success = false;
			for (var i=0;i < MSXML_XMLHTTP_PROGIDS.length && !success; i++) {
				try {
					xmlhttp = new ActiveXObject(MSXML_XMLHTTP_PROGIDS[i]);
					success = true;
				} catch (e) {}
			}
			if (! success) {
				alert ('No AJAX-Support for this browser :(!');
			}
    }
    return xmlhttp;
}
var http = createRequestObject();

function callInProgress(xmlhttp) {
    switch ( xmlhttp.readyState ) {
        case 1:
			  case 2:
			  case 3:
            return true;
        break;
        default:
            return false;
        break;
    }
}