monitor screen orientation

I know there are libraries for setting screen orentation, but what about watching for screen rotation? The only work around I could think of is using a tmer tick to cross refrence a previous value. example:
Sub app start
screen.width = a
end sub

Sub timer1_tick
if screenwidth=a then
else
resize controls
screenwidth=a
end sub

obviously not a word for word working example, just an explaned concept. This way seems waaayyyy to memory intensive though. Is there a library or a way to hook the screen rotation event from the door library? I have searched with no avail and yet i'm pretty sure its possible.

If you have WM 5.0 or later then you should be able to monitor the DisplayRotation SystemProperty and be notified if it changes with my http://www.b4x.com/forum/additional-libraries/3346-systemstate-library-wm-5-0-later.html

Hi!

I normally use the resize event from the formlib to monitor screen orientation changes. If you have multiple forms you have to create a new formlib object for every form but it works well in my applications.

Greetings,
Markus

Thanks guys, i went with the flib example for now since i was already using that library for some text alignment. You guys can check out the project i'm working here if you like:
[APP][UPDATE June 3] "OpnMarket" Freeware Market/ AppStore [Beta Testing Now] - xda-developers