Forms Always on top?

Dear all,

    How to make more than one Forms of my application stay-on-top? Because
Delphi cannot set non-mainform stay-on-top. Even I use SetWindowPos API.

    Someone tell me SetWindowPos(Application.Handle, ...), but this seems
not work under Windows 2000. When user swap focus to other application, my
application cannot stay-on-top any more!

    Someone tell me set all forms to mainform of my application, so I can
set all forms stay-on-top. But I don't know how to do that.

    Can anybody help me?
    Thank you

Samson Fu