pop up windows

here's my problem.

when using those two pieces of script to create a pop up window in which my pictures for my website are displayed there is no problem. the problem arises however when i then click a link on the original page (from which the window was launched). instead of it changing what page is displayed it opens up a new window. this only happens however once the window has been clicked to viewpictures. the links i am clicking are in a different frame so why does this happen and how can i stop it?

i have not explained my self very well so please go to:
1) http://www.goecities.com/sparky_132/
2) click gallery on the links at the bottom of the page (in a different frame you'll notice)
3) click wallpapers
4)if you then click home for example it will display it in the correct frame.
5) if however you click on a thumbnail and open up the window displaying the picture, close it and then click 'home' it opens up a new window instead of displaying it in the correct frame.

how do i stop this happening?

also on the main page 'home' the background will be tiled (if u use a big resolution like me) how do i stop it tiling?

thanks