Checking if MC exists

I have a gallery loading jpegs from an xml file into a mc called mainPicArea, on frame 5. I have other content on frames 1,2,3,4,6,7.

I want to run an if statement to check whether mainPicAreaexists and if it does, then run a removeChild(mainPicArea), and if not do nothing.

if (MovieClip.mainPicArea){
trace(“doesent exist”);

this is my code.

When I test, it comes back with the trace “doesent exist”, even though it does exist.

Any ideas much apreciated