Menu creation.

Hello everyone. I'm creating a menu based on the Xazardous mod. However, I have a widescreen image, and there's black space displayed on the right! (Xazardous also has black space there). Could you tell me where the background textures are located? Also, how do I change the size of the allowed icon or image? I suspect that everything is hidden in the *.xdb files; please help me understand them.