Help with motion menu and menu size

I am pretty new to encore so this may be an easy question to answer. I am making a motion menu and I captured some video, 720x480, from my camera. I link the video to the menu and it seems to work fine. However the menu has dimensions of 720x536 and with the video it leaves a black bar at the bottom of the menu. How can I make the menu smaller to position the video correctly.

Thanks in advance.

Joel