'if' function on button

hey, im a little unsure about how to do this - im sure its fairly simple, but i want my button to have a different action depending on whether an mc is playing - basically i have a few buttons, each with their own actions. but if one button has been pressed, id like the other button to close it’s movie before performing its own. i can put in the actions myself, im just unsure how to use the button with an ‘if’ function kinda thing. i hope someone can understand what im saying :stuck_out_tongue: and help me out.

cheers