1. I am generating buttons using the slicer tool that came with sencha sdk. My buttons have rounded corners. When the buttons are generated, the background colours of the corners are white in color. Is there any way to change this, e.g. to transparent gif or png?

2. For some buttons i would like the top right, and bottom right to have rounded corners, and top left and bottom left to be squared. Is this possible?

Thanks in advanced!