Flash MX button-actionscript error

Hello. I have a flash document with multiple scenes, each containing several layers. I have tried to link scenes using buttons with the 'gotoAndPlay("Scene 2", 1)' or even 'gotoAndStop' (even though I really didn't want it to stop at frame 1, I was trying to figure this thing out on my own first), and I keep getting the following error:

**Error** Scene=Scene 1, layer=buttons, frame=45:Line 2: Statement must appear within on handler
mom_btn.onRelease = function (){

Total ActionScript Errors: 1 Reported Errors: 1

I've sucessfully linked scenes using the premade tutorial material, but now would like to branch out on my own. And I can't figure out what I am doing wrong....can someone please offer some sage wisdom on this matter? What does it mean, "Statement must appear within on handler....?"

"handler" I think meanS you need to assign an action to your button. On release, click etc. For example,

on (release) {
CODE GOES HERE
}