Oracle Forms

I have migrated a Forms 6i application to a Forms10g application that runs on the internet. The original forms created in 6i were created for 800 X 600 screen resolution and hence I gave similar entries in my formsweb.cfg.
The users who now use a screen resolution of 1024 X 768 complain that the full screen is not being utilised while the ones on 800 X 600 are still happy.

If i set the height and width parameter in formsweb.cfg to 100%, the applet area fits perfectly to the screen resolution, but my form canvas (being 800 X 570) is anchored at the left, leaving a gap at the right side and bottom. The menu however expands to the complete screen.

Is it possible to expand the form's canvas / window size depending on the screen resolution at run-time?