Add login to script

I have an auction script that is written in PERL. The script currently allows public viewing of the auction listings. A login (with a cookie) function is already built into the script and log in is required to access certain functions such as listing an item to the auction, viewing closed items, etc. I would like to require a person to also be logged in to view the auction listings. I have uploaded the file containing the current sub routine to display an item that is listed for auction. The sub already checks if the user is logged in, and if they are, the username and password form that is required to bid is autofilled. It seems (to me) that that what is already there might be added to so that if the user is not logged in, they are sent to the login page instead of the item display. If they are logged in and have received the cookie of course, I'd like them to go directly to the item display. Thank you.