attachMovie and removeMovieClip

programming flash
1

Hi,
I have been trying to solve this problem for times but still unable to solve it…>.<

I have placed an empty Movie Clip with instance as emptybg


  if (empty1.hitTest(_xmouse,_ymouse,false))
  {
   emptybg.attachMovie("bg1","blue",1);
   setBackground = 1;
  }

but when i wanna clear the attached movie clip,
I typed


on(press)
{
 setBackground = 0;
 emptybg.removeMovieClip();
}

but still unable to work >.<
Thanks in advance for the help offered…

Regards,
Lacus