I want to protect a drawer on my new desk using an electro-magetic lock. I need a step- by- step guide to build one, and how I can unlock it. THanks to anyone who can help me!

It is like a standard padlock but is opened with a magnet instead of a key or combination.

I am interested in attaching a lock on my door, but as a locksmith, key locks are useless against trained, or a kid who pratices. After some research, I would like to use either magnetic swipe cards (I call them "credit cards with no value"), or proximity cards (An example is ones made from HID that is used as an entry system). What will I need and what will I need to do for each system? Estimated costs?