I am trying to make an animation (transition) on a button useing actionscript and calling the MC from the library to the button. Problem is I get an error when I run it

**Error** Scene=Scene 1, layer=Layer 1, frame=1:Line 1: Expected a field name after '.' operator.
myButton.on(rollOver)=function(){

**Error** Scene=Scene 1, layer=Layer 1, frame=1:Line 4: Expected a field name after '.' operator.
myButton.on(rollOut)=function(){

Total ActionScript Errors: 2 Reported Errors: 2

I dont understand what this meens.

my code on the frame is:

myTargetSwitch1 = "off";

_root.mcFadein.onEnterFrame=function(){
if(myTargetSwitch=="off"){
this.gotoAndStop('stopped');
}else{
this.gotoAndPlay('fadein');
}
}

and the code on the button is:

myButton.on(rollOver)=function(){
myTargetSwitch1="on";
}
myButton.on(rollOut)=function(){
myTargetSwitch1="off";
_root.mcFadein.gotoAndPlay('fadeout');
}

does anyone have any suggestions?