Protect images in directory

I think this question has been asked before, even in PHP Builder, but I still haven't seen a plausible answer. :) Basically, I want to protect images in a folder (it's for a family album thing). It's going to be on a Linux server and I plan to use .htaccess to protect the folder. Is there a way to use custom forms (the usual ones with the Submit button) to allow people to enter the said folder, and not use the usual pop-ups that IE or Netscape or any browser presents the user with? I don't want want people to be able to leech the images without entering a password. Thanks in advance for all your help. - Kyutums