Right front window stuck in up position on 1998 BMW 323is

What would be the process to check if one of parts that make the window work so i wont buy the motor or regulator first?

Asked by for the 1998 BMW 323is
Here is a quick test: With the key on, hold the window switch for the affected door in the down position and open and close the door firmly a few times. If the window starts working the fault is most likely with the window motor. If nothing happens, the next step would be to remove the door panel and perform some basic electrical diagnosis to isolate the fault.