How do i load an external mp4 file inside my audio file to stage using code?

35_JunTing_asm01.zip - Google Drive  This is my current file, Is my code correct? from line 106 onwards in "Learn More" frame 1 actions code and is the loader to load the mp4 file correct? It doesn't seem to load from my audio file instead it just plays from the video i imported onto the stage I'm certain on that as i tried to do the removeChild method in line 133 and it didn't work, hence i added the 2 lines of codes after that line.

Can any expert help me on the code? As i'm still a beginner i would really appreciate if you could send me the code to rectify the problem or send me a step by step instruction to solve this issue