Why cant i gotoAndPlay?

now, i’m not an ActionScript guru…so bear with me.

is anyone else having problems adding actions to MC buttons? with FL8, i’d select my MC button, open my AS panel, then give it the desired actions ( i.e. on ( rollover ) gotoAndPlay this, on ( rollout ) gotoAndPlay that )
…i know this isn’t the correct script, it’s just an example…

however, with AS3 ( in the Behaviors panel ), i keep getting a message that says AS3 does not support what i’m trying to do.

i’m obviously doing something wrong but why has it been changed? and what do i do now to get the desired actions i need?

thanks for listening,
Andre