Scratch

I have my Sprites all clickable and if you click on a wrong Sprite it'll say like "Try again!" or "Not me!", but when they do find the correct Sprite it tells you its correct and to click the space bar.
My first level is complete and goes to the 2nd level just fine but I don't know how to make the 2nd level go on to the 3rd level and so forth. I'm trying to make at least 5 levels.
But if so, could anyone please help me?
I need to finish it by tomorrow and I need help.

Thanks!