function postText()
{
    var chatbox = getElement( "utext" );
    var chat = chatbox.value;
    chatbox.value = "";
        
    var url = AjaxServerPageName+"?active=addtext&user=" + getuser + "&userid=" + getuserid + "&text=" + chat;
    
    var req = getAjax();
    
    req.onreadystatechange = function(){
    
        if( req.readyState == 4 && req.status == 200 ) {
            req=null;
            updateAll();
        }
    
    }
    
    req.open( 'GET', url, true );
    req.send( null );
    url=null;
    chat=null;
    chatbox=null;
}

Response.Charset = "gb2312";
//下面才使用Response.Write