zoran, if your image's size is, lets's say, 200x100 and your cell's size is 100x50 there is no way of cutting that image off to fit in the cell as a background image.
All you can do is to play around with the
background-position style attribute and see what you can do.
background-image: url('main.gif');
background-repeat: no-repeat;
background-position: [bottom] [center] [left] [right] [top] [inherit];
You can play around by mixing these values
:
background-position: bottom center;
or
background-position: left top;
....
hth
