提示框加载的效果。具体请看图，不会描述

点击确定后
会这样。求告知怎么弄！！

http://docs.sencha.com/extjs/4.1.3/#!/api/Ext.window.MessageBox-method-show

 Ext.MessageBox.show({
           msg: 'Saving your data, please wait...',
           progressText: 'Saving...',
           width:300,
           wait:true,
           waitConfig: {interval:200},
           icon:'ext-mb-download', //custom class in msg-box.html
           animateTarget: 'mb7'
       });