Fill the screen?

[TheShaner]

This is a totally stupid question, but I cant figure it out for the life of me.  When I was using vanilla MAME, things fit the screen.  Now that I am using GroovyMAME, i believe the original pixel / screen size is being used.  Can I use a command line switch on certain games to fill the screen, while keeping the aspect ratio?  Or what about if I include a bezel, anyway to stretch to where the bezel hits the outside edge of the screen and fill mame inside?

Thanks!

[TheShaner]

Ok, figured it out.  In the video options, the artwork needs to be set to crop.