Margins flow round the entire frame. You cannot operate on them individually but you can operate on the vertical and horizontal margins separately.

That means the top and bottom margin must be the same, as must the left and right.

This property is the size of the margins to the left and right of the frame.

This is a bit like the hspace property but since neither seems to have any effect - it is difficult to prove that they operate independently.

Warnings:

• This seems to have no visible effect in MSIE and Netscape.