I now need help on buttstomp block... How do you do them?

I thought I could just place some tiles there, and a event on them, BUT NOOOOOO after i put the event in, in the test run, the block disappers, but you get points for buttstomping down.

ack...

However, the level is doing great! should be done the the miuddle of this month! (I have a lot of things to do, so I at least put in a hour each day. )

see ya!