Argh annoying flash

Hi there, what I am trying to do is have a main page (stage) where there are 3 buttons and once clicked they will display a text box.

now I have created 4 buttons, and I have also created 4 movie clips. The movie clips are on the main timeline as are the 4 buttons, I just used a small white box so I could access the movie clips. now within the movie clips I have the text block and the following action script on a seperate layer

stop();

this._parent.superman.onRelease function = () {
gotoAndStop(20);
}

and I get the following error

Error Symbol=text1_mc, layer=text, frame=1:Line 3: Syntax error.
this._root.superman.onRelease function = () {

Total ActionScript Errors: 1 Reported Errors: 1

Can anyone help me?? I 've been at this **** thing for 5hours now and I am starting to get really frustrated / annoyed with this as I cant figure out what is wrong with it