How to control or link external.swf movie from a button on the main movie.swf ?

You have a movieclip called "container". Within this, you load a movieclip that IS NOW CALLED "container".

So, when you want to reference the external movie, you do it like this:
_root.container.container

If you want to move to a frame, for example, assign this actionscript to a button on the menu:
on (release) {
    _root.container.container.gotoAndStop(2);
}

Now when you click the menu button, the external clip will move to frame 2. Is this something like you wanted?

Hi bupper in response to your question is NO.

In my maine.swf movie I have a movieclip with the instance name call "container" this empty movieclip load inside my external.swf movie with the following code :

stop ();
this.createEmptyMovieClip("container", 1);
container.loadMovie("external.swf");

Now on my external.swf movie i have a movieclip with the instance name call "pages" inside this movieclip I have 5 frames labels called up "p1","p2","p3","p4","p5"

So my question its how i do to communicate from my button 01 btn ( inside menu mc > main.swf. ) to my external.swf movie to my > movieclip with the instance name call "pages" and goandplay the frame label call "p1" ?

Check this link example here :: Follow the red arrow !

http://enixstudio.com/flash_tutos/how_to_control_external_movie_tuto/control_external_movie.html

if my menu was in the same movie lets say main.swf iknow this code works to call each frame label from my button 01 btn to > movieclip with instance name "pages" > to > my frame label call "p1" and works for each button !

on (press)
{
    if (_root.link != 1)
    {
        _root.menu["item" + _root.link].gotoAndPlay("s2");
        _root.link = 1;
        _root.pages.play();
    } // end if
}

Check this link example here ::

http://enixstudio.com/flash_tutos/how_to_control_external_movie_tuto/crane_and_menu.html 

In brief  I need to do this but with my menu in my main movie and my pages on my external movie.
 
and thanks for the help but I hope you can help me a bit more ! : )

this is so odd, i'm sure I posted something on your topic this morning. oh well, maybe it was too early in the morning.

enixstudio what bupper is saying is correct.

not sure what your _root.link etc does, but the problem is here

_root.pages.play();

as bupper says

  _root.container.container.play();

Thanks bupper and blue-genie for your attention and patience works to perfection and how you said you do not need the lockroot !

As a contribution i upload the files for people in need in the future:
 http://www.enixstudio.com/downloads/tutorials/flash/how_to_control_an_external_swf/main.html