drawing question

1
Can someone tell me how to use fillpoly in screen?
It says,

Screen('FillPoly', windowPtr [,color], pointList);

What is a pointList? I've tried everything I could think of. I just want to draw a bar (rect)
that I can rotate with a function I've written for that purpose.

If someone could send me an example that draws a oh say 5 by 20 filled rectangle using
FillPoly, it would save me a lot of time and frustration. :)

Ray