Hi Weibin!!! Welcome to the Expresso Mail Help files. These are actually HTML files which you are viewing with the Swing JEditorPane component. Pretty cool, eh? Were this an actual program, these files would contain helpful tips and instructions. Since this is not a real program, but only a demo, there is a random smattering of information contained within. This is simply indended to show what is possible. Click on the links below for more information.