last viewed page

after logging in i would like the user to be redirected to last viewed page on the site before logging in. I’ve searched for hours on this forum and google. no results. i have a simple log on form at the top of my page in the header. nothing fancy. I think i would have to edit the wp-login.php but that’s a static page only. more info at end of post. Any help would be GREATLY appreciated. thanks in advanced for your time reading this and any possible solutions!
wordpress version 2.7
site: https://tamtrades.com (click the quick login)