1. 图片
var globalMask = new Ext.LoadMask( Ext.getBody(), {msg:"<div class=\"maskcls\"><img src='<%=rootPath%>/images/waiting.gif'></img></div>"});
2. 文字
var globalMask = new Ext.LoadMask(Ext.getBody(), {msg:"Please wait..."});
调用
//显示
globalMask.show();
//隐藏
globalMask.hide();