Controlling multiple movie clip location using single function

programming flash
1

I need to write a function which should fix the location of the movie clip on the stage.

public function setCoOrdinates(xpos:Number,ypos:Number,movieName:String):Void
{
eval(movieName)._x=xpos;
eval(movieName)._y=ypos;
}

My function is as above. While I use this function in flash I only see the last movieclip on the stage which was passed. Movieclips passed earlier seem to have disappeared from the screen.

    setCoOrdinates(20,200,"bButton_mc");
    setCoOrdinates(530,100,"fButton_mc");

I see only “fButton_mc” on the stage. Even though I set different xpos and yposs for the movie clip.