Button control Movie clip

It is not clear from your description where the different object reside relative to the main timeline.  One way to approach a design is to keep all of the code in the main timeline to make it simpler to determine the path to targeting different objects.

If the button is inside a movieclip and Pannel_m is also in the timeline that the movieclip is in then you would have to use a Movieclip(parent) reference to target back to the parent timeline.  But if you place all the code in the main timeline it becomes easier to manage the targeting because everything has the same reference basis.

The following works if Pannel_m is in the same timeline as the Buth_CathRed

Buth_CathRed.addEventListener(MouseEvent.CLICK, fl_ClickToGoToNextFrame_2);

function fl_ClickToGoToNextFrame_2(event:MouseEvent):void

{

     nextFrame();

     Pannel_m.gotoAndStop(2);

}

The following works if Pannel_m is in the same timeline as the movieclip that contains Buth_CathRed

Buth_CathRed.addEventListener(MouseEvent.CLICK, fl_ClickToGoToNextFrame_2);

function fl_ClickToGoToNextFrame_2(event:MouseEvent):void

{

     nextFrame();

     Movieclip(parent).Pannel_m.gotoAndStop(2);

}