Button to call function

I ahve abutton function that I want to go to another function. it works but then it doesn’t use the onComplete I ahve for that function ( using tweener). Then the movie starts jumping around and the timing is off ont he elements.

I guess the button is calling the right function but when it fires and executes it then it start messing up.

This is the code I’m suing to call on another function in my code:

btnNext1.addEventListener(MouseEvent.CLICK, featureNext1);

function featureNext1(event:MouseEvent):void

here is the function that is executed, but then the onComplete part doesn’t work.

function featureimg1(){
        Tweener.addTween(features, { x:26.9 , alpha:1,time:.75, onComplete:timer1, transition:"easeInExpo"});
        btnNext1.y = 215;

This is for a slide show that I’m making that has next and previous image buttons.
I would really appreciate some incite into this.