I have a drop down menu system with 5 different buttons - I need each button to load a different swf file into a movie clip on the stage - at the moment the code for the buttons reads

on (release) {
loadMovie("yourfile.swf",_root.oneClip);
}

how do I program it so that when I movie has loaded and the user chooses another button, it unloads the previous movie and replaces it with a new one?

Please help!