Can't get widths of divs to align

Question

On this page (http://www.comehike.com/hikes/hiking_group.php?hiking_group_id=2), I'm trying to get on the right side, to have the button for "join group" to

1. Have the same botder width as the div above it
2. Leave at least a little white space before the ad that comes right below it

I am trying to do something like this:

<div style="width: 285px; float: right; border: 1px solid; padding: 5px;">

But adding the padding just made the div wider, and didn't make any space to the bottom.

Any idea what I can do? Thanks!

Answer 1

Do margin-bottom instead of padding-bottom