This isn't the right movie?

I clearly bought a ticket to see Step Up 2: The Streets, but for some reason you guys are showing The Dark Knight. What's going on? This most definitely isn't the right movie! What do you mean it's a trailer for The Dark Knight? OHHHHH, I see you mean it's like a preview....ohhhh....OK, I understand. So you will be showing Step Up 2? OK! For a second I thought I walked into the wrong movie. Ha! Isn't that funny? I can't wait to tell all my friends this delightful story, I'm sure they will amused. Thank you!