AS debugging

Hi, im wondering if anyone can help me I have just finished doing a tutorial that is AS based. But I have stumbled across some bugs that I cannot figure out. I am new to AS and underatand the basics of the code but help would be greatful. I would like it if someone could explain why this app. was not working and how the resolved it.

PS. I am uploading from an external source as well, if that helps.

Cheers

Craig