How to check if a form has the focus?

Hello,

I use vb.net 1.1 and have 3 forms called respectivelly f1, f2 and f3.

I use to have the following code working. I have no idea why it has ceased to work. All that is different is the PC the software has been installed on.

if f1.focussed then
...
elseif f2.focussed then
...
elseif f3.focussed then
...
end if

for some reason I do not understand, focussed always returns false regardless of the focus state.

Is there another way to identify if a form has the focus?

Thanks