I have a send keys app right now. I would like to be able to use the same functionality but send keys to a non active window. This way I will be able to use a stop function and also be able to work with this app runnign in the background. The send keys is just very dangerous if the window focus changes, and it is dificult to stop without putting stop code in every other line to check the window with focus. So can I use send message to send keystrokes to another old application for data entry? And if so, what is the correct way to use send message?