OpenOffice.org create form checkbox with no border
 

I'm creating a form in OpenOffice.org and I'd like my checkbox to have no border. So a check is printed if the box is selected and nothing is printed otherwise. This seems to be a little more difficult than you'd think. So far all I've seen to adjust the appearance of the box is flat vs 3d.

Also, I'd like to be able to customize the size of the box a little. However when I try to expand the object, the checkbox remains the same size and the object expands to uncover a label...