PLEASE HELP ME ASAP TypeError: Error #1009: Cannot access a property or method of a null object

[nabuwel]

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at finalnewmma1_fla::MainTimeline/frame3()[finalnewmma1_fla.MainTimeline::frame3:1]
at flash.display::MovieClip/gotoAndStop()
at finalnewmma1_fla::MainTimeline/goHome4()[finalnewmma1_fla.MainTimeline::frame9:6] 

THIS WAS MY PROBLEM AND I TRY TO FIND SOLUTION ALMOST A DAY, AND I NEED TO SUBMIT IT THIS TOMORROW

this is the coding at page in frame 3 

imgs_btn.addEventListener(MouseEvent.CLICK, goImages);

function goImages(e: MouseEvent): void {

gotoAndStop('images');

}

vid_btn.addEventListener(MouseEvent.CLICK, goVideo);

function goVideo(e: MouseEvent): void {

gotoAndStop('videos');

}

mnm_btn.addEventListener(MouseEvent.CLICK, goGame1);

function goGame2(e: MouseEvent): void {

gotoAndStop('game1');

}

grab_btn.addEventListener(MouseEvent.CLICK, goGame2);

function goGame1(e: MouseEvent): void {

gotoAndStop('game2');

}

[kglad]

imgs_btn doesn't exist at frame 3