var xmlHttpRequest;
function getXMLHTTPRequest(){	
    var xmlHttpRequest = false;
    try{
        if( window.ActiveXObject ){
            for( var i = 5; i; i-- ){
                try{
                    if( i == 2 ) {
                        xmlHttpRequest = new ActiveXObject( "Microsoft.XMLHTTP" );    
                    } else {
                        xmlHttpRequest = new ActiveXObject( "Msxml2.XMLHTTP." + i + ".0" );    
                        xmlHttpRequest.setRequestHeader("Content-Type","text/xml");
                        xmlHttpRequest.setRequestHeader("Content-Type","GBK");
                    }
                    break;
                } catch(e) {
                    xmlHttpRequest = false;
                }
            }
        } else if( window.XMLHttpRequest ){
            xmlHttpRequest = new XMLHttpRequest();
            if (xmlHttpRequest.overrideMimeType) {
                xmlHttpRequest.overrideMimeType('text/xml');
            }
        }
    }catch(e){
        xmlHttpRequest = false;
    }

    if (!xmlHttpRequest) {
      alert('´´½¨XMLHTTPRequest¶ÔÏóʧ°Ü£¡');
    }
    return xmlHttpRequest ;
}
function sendGetRequest(xmlHttpRequest,url,functionName,sync) 
{  
	xmlHttpRequest.onreadystatechange = functionName;
	xmlHttpRequest.open('GET', url, sync);
	xmlHttpRequest.send(null);
}