But you then you may have to do some adjustment to make it line up properly for all headings, and to stop the text jigging about when you mouse over.
Easier would be to leave the css alone (on this occasion) open the left.jpg and right.jpg from the image folder and chop 15px off the right of the right one, and 15px off the left of the left one (so both are 13px wide). Then the menu will not dance about and the heading text will be centred in each one.