I have typical replacement windows that are about ten years old in my house. My boys managed to break one of the piece pictured below. (Actually, I've pictured the one that isn't broken).
This piece screws in at the bottom of the window, and allows the window to pivot so that you can easily clean the outside. It also is essential for the window to stay up.
I'm sorry that I don't have much vocabulary to talk about these things.
My question is: what is this piece, and how do I find a replacement?