Trouble with gotoAndPlay and movieclips

[IDdaniel]

hello,

I have been working on a product design portfolio in flash CS5.5, and have run into some trouble with my AS. I managed to eventually fix the problem, but was hoping to get some feedback as to why it wasn't working in the first place.

I have a movieclip
I have a button(

btn_01)

and a movieclip(P_01) on the main timeline. The P_01 movieclip contains an empty stop frame on frame 1. From frame 2 to 20 an image fades in and stops at 20, then 20 to 40 the image fades out:

This works:
this.btn_01.onRelease = function (){
if(this.P_01._currentFrame <= 20){P_01.gotoAndPlay(21)}else{P_01.gotoAndStop(20) }

This Doesn't:
this.btn_01.onRelease = function (){
if(this.P_01._currentFrame <= 20){this.P_01.gotoAndPlay(21)}else{this.P_01.gotoAndStop(20)}

I would prefer to keep the scripting relative to its location with the "this." function, as I want to keep all the scripting contained within the movieclip.

thanks in advance,

Daniel

[TheCanadian]

this contextually refers to different things. Outside the function, this refers to the MovieClip on who's timeline the code was written. Here, I think it would be the main timeline, _root, but your description was confusing to me. Inside the function, this refers to the object in which the function is defined. So in this case, inside the function, this refers to _root.btn_01. In essence, you're writing _root.btn_01.P_01.

[IDdaniel]

Thanks for the reply 'The Canadian'. I originally posted it as I was running out the door, and now reading it I can see the confusion. Your reply made sense and is very helpfull.

Thanks again,
Daniel