// JScript File

//构建 ajax 的核心对象
function getXMLRequester()
{ 
    var xmlhttp_request = false; 
    try
    { 
        if( window.ActiveXObject )
        { 
            for( var i = 5; i; i-- )
            { 
                try
                { 
                    if( i == 2 )
                    { 
                        xmlhttp_request = new ActiveXObject( "Microsoft.XMLHTTP" ); 
                    }else{ 
                        xmlhttp_request = new ActiveXObject( "Msxml2.XMLHTTP." + i + ".0" ); 
                        xmlhttp_request.setRequestHeader("Content-Type","text/xml"); 
                        xmlhttp_request.setRequestHeader("Content-Type","gb2312"); 
                    }
                    break;
                } catch(e)
                { 
                    xmlhttp_request = false; 
                } 
            } 
        }else if( window.XMLHttpRequest ){ 
            xmlhttp_request = new XMLHttpRequest();
            if (xmlhttp_request.overrideMimeType)
            {
                 xmlhttp_request.overrideMimeType('text/xml'); 
            } 
        } 
        }catch(e){ 
        xmlhttp_request = false; 
    } 
    return xmlhttp_request ; 
}