StayOnTop forms - question

In my little program I have two forms: the main one and the mini one. I
would like the mini_form to stay on top of all other windows.
The problem is:
when I set the forms style to fsStayOnTop the mini form stays on top of the
main form but not on top of any other window.
How to create a global StayOnTop form ?


I have tried
   mini_form.Top,  mini_form.Width,
but this does exactly the same thing.