does anybody have an idea about my question above?
you need to edit the output of webhelp,
Go to the webhelp output folder and open the file whskin_mbars.htm in notepad.
search for <body tag and add the following style
style="border-top: 1px solid red;"
in case you want to make the border top as red color or make it any color you want.
Thanks very much for your reply, this answers my question!