Plays movieclips on timeline

1

Hi, i have one page on which there are 4 images. for each images i have added mouse event listeners . that means whenever i 'll click on particular image respective movieclip will play.

I have taken movieclips on timeline. so my code is :


stop();

gt_mc.buttonMode=true;

gt_mc.addEventListener(MouseEvent.MOUSE_UP,GT);

function GT(e:MouseEvent):void{
    gotoAndPlay("gt");  // this movieclip is on frame no 3.

}

/////////////////////////////////////////////////////    
cm_mc.buttonMode=true;
cm_mc.addEventListener(MouseEvent.MOUSE_UP,CM);

function CM(e:MouseEvent):void{
    gotoAndPlay("cm"); //this movieclip is on frame no 4.
    }
////////////////////////////////////////////////////////

when i’m clicking on button gt_mc, particular movieclip play with sound finely.

** but whenever i’m trying to click on button cm_mc, it plays particular movieclip but first movieclips sound also plays in background.

why is it so?

i have heard abiut addChild property, how can i use them here to solve my problem.

Any other method will be acceptable.