Avatar Help

I have an avatar. It is 100 x 75, but the board keeps saying the file is too big. I am technologically challenged, so could someone help me and make it the size the board will accept?

If you can, thank you so much.

this should probably go in here http://www.killermovies.com/forums/f76/t18944.html

Actually, the Sig Help thread would be better.

And it's because the file size is too big. It has to be 20kb or under. Yours is 255kb.