Centering my movie file!

my movie file takes up all of the 800x600 pixels I’ve given it, but sits in the top left corner of my browser once published. the tutorial on centering it in the browser claims that I should simply change the dimensions in the publications tab to 100%x100%, with no scale. When I do this, the published html file has an itty-bitty version of my movie in the top center. Is there any way I can get an 800x600 version centered on anyone’s browser, regardless of their resolution?

Previously, I had been told to use a table… not too sure how to do that, or if it’s even necessary. Thanks a lot!