Stop at last question

Hello

I have a multiple choice quiz and i want it to stop on the last question. Can you please help
here is my code -

numExamples is the length of the array

this what my next button

var index:int = 0;

btnNext.addEventListener(MouseEvent.CLICK, goNext);
function goNext(mevt:MouseEvent):void {
index++;
if (index > (numExamples - 1)) {
index = 0;
}
setup();
}

And the setup function basically makes the the radiobuttons according to the answers