Try picking it with a bobby pin. If that doesnt catch the lock, you may have to bust it open =(

Do it the way your parents do it and use a hairpin.

"Lock picking with a paper clip. With two paper clips you can pick a padlock. It's simple and you'll be able to open the lock easy. As seem in the movies. Firstly bend the paper clips into a tension wrench and a pick. The first paperclip that is chosen as the "pick" (you lift up one edge of the paperclip at a set angle) make the paperclip look like a resemble "r". Then to make a tension wrench open up the paperclip and then twist one end of the paperclip on to the other. Make sure there are minute gaps between the twists. Once you have the pick and tension wrench bent into shape, you can begin picking the lock. Firstly, put the tension wrench into the bottom of the keyhole and push it in. Apply tension to the end of that paperclip clockwise direction. You need to sustain tension on the tension wrench (while you insert the pick). Insert the straight paperclip into the top of the keyhole. Then find the pins and push them down then rake and viola. No need to call a locksmith in when you have two paper clips in your pocket and a locked padlock." Source and further information: http://www.gomestic.com/Do-It-Yourself/Got-a-Paper-clip-Pick-a-Lock.24526 Further information: - "My diary has a lock on it and I lost the keys How Do I pick the Lock? I've tried everything from door keys to pushpins.": http://www.answerbag.com/q_view/1043736 - "I LOST MY DIARY KEY...?": http://answers.yahoo.com/question/index?qid=20090224150226AAPJT98 - "How to open a diary when you lost the key!!?": http://ph.answers.yahoo.com/question/index?qid=20070813223856AA2RTrG - "I have a small diary lock and i lost the key how can i open it ive tried paper clips?": http://answers.yahoo.com/question/index?qid=20080909072645AAO23DN