I use the sysmetric(1) and sysmetric(2) to check width and
height of the screen. When 800 X 600 screen is detected,
I reduce my screen which I created under the 1024 X 768 by
75% by multiplying the width of my screen by 0.75.

I start of with

If sysmetric(1) + sysmetric(2)<=1400
mreduce=0.75
else
mreduce=1
endif


Object.width=width*mreduce

It might not be best was but it solve my problem.