i dont really remember but i think it's middle button of mouse
edit: yep its mmb
sorry for the R E A L L Y late reply i had to get a new computer also IM BACK I CAN FINALLY PLAY MY FAV GAME MADE BY MY FAV GAME MAKER PERSON!!!!!!! also idk what you think but i relly wanna be part of a game so i could do some music for one or art for one for you? but my art and music are poop so if you decline i dont mind