Append to ClipEvents?

hey there. i was wondering the other day about how i would add actions to a currently running clipevent. example

clip.onEnterFrame=function(){
this.dosomething();
}
and then if i wanted to have it do something and something else, but i didn’t know exactly what it was currently doing

clip.onEnterFrame=function(){
this.onEnterFrame //and add something else?
this.dosomethingelse();
}

i just want to add something to onEnterFrame ?

anyone