Button Dilema - Please help!

Hi Everyone,

I am trying to design an interactive flash piece, where, once the button has been clicked, it goes to:

Firstly: a state that says … “im here” and shows content

When another button has been selected (clicked), the first button shows
a state that says … “I’ve already been clicked” (alpha state of 50%)

I’ve already worked out the first part, but cant work out how to do the
“I’ve already been clicked” state …* is it actionscript ???
*
If so, HOW ???

Please Help I have a deadline thats today
I’ve searched for tutorials etc, but cant find anything that will teach me how to do this

I,ve attached the zipped fla … to make more sense of what I’m doing.