</body> tag

Hi, I need to place a code right after the </body> tag. I thought it would be in the footer template, but it is not there. Where can I find that tag?
thank you

[Lesane]

In the forumhome template

[Lionel]

I placed it in the showthread template. It's a neat dhtml poup that you cannot closeand that self closes after x seconds to non registered users only and I use it to display ads.