Simple Movie_Clip function (help)

Hi,

I wonder is there a simple answer to this this question:

I have a moviclip on the main stage with a stop action on the frame above.

I want the movie to play ahead from that frame on the main stage after a certain frame is reached in the movieclip.

I tried using this simple function on the main stage;
if (_root.myMovieclip.signal._x = 100){
gotoAndPlay(win);
}

So when signal._x moves to 100 in the movieclip, the frame jumps to “win”. However this doenst work . I tried using a timer on the frame as well but it does not provide an accurate enough response.

Any help would be much appreciated…