If you have a lot of interior doorknobs with key locks on them, sooner or later you're bound to lose the key or lock them inside the room. Here's what to do to get back in.

When one of my interior doors got locked with the keys inside recently, I learned all I ever wanted to know about lock-picking and doorknob assembly. Locksmiths are expensive, so let me share everything I tried and show you how I eventually got the door open.

If the doorknob in question is a simple push-button affair, most of the time all you need to do is jab a paperclip in the hole and push on the locking mechanism. If the doorknob just has a slit on the outside handle, a butter knife shou...