Does anybody know how to bookmark a search?

I've got a half-finished site displaying articles from a magazine. You can search for articles by keyword, issue, etc.

Now I'm working on an editing function, which will allow authorized users the ability to change pictures that go with their stories. To do this, I've made a 'changepic.php' page which is called by the main search page.

When I get to the changepic page, I can use the variable "$SEARCH-STRING", to build a bookmark that goes right back to the original search. But when I submit the form to update the query, of course the SEARCH_STRING variable is also updated, destroying my bookmark just when I need it.

Does anybody know how to keep this variable alive or is there a better way?

You can see what I mean by going to the site at http://www.wordpix.ca/sportrep/

Thanks