Problem with Key.isDown w/ movieclip

1

www.soul.clearphp.com/soul/soul.html
1024 resolution you can register or just use this

username:
password: ----
^ leave username blank

when your loaded press backspace how do i make it smooth? like for example when i click the backspace it opens and closes it, right now im using setinterval so for a second if you click backspace it doesnt open

my code is something like


onClipEvent(enterFrame)
{
setInterval(whatever,15);
}

function whatever()
{
 if(Key.isDown(Key.BACKSPACE))
{
// menu _visible thing
}
}