Load movie and array questions

hello folks. My first question is regarding a problem i am having. I have a movie clip on my stage with an invisible button inside of it on layer 1. on run time i tell the mc to load a jpg and it does just fine but it overlaps the invisible button. is thee any way around this?

second question. i have an array hat stores some names nothing special. and i want to randomly pop a name out of the array and place it into a new array.

i tried
myArray.pop(Math.floor(Math.random()*myArray.length));

when i ut that on a button it pops out the last item in the array