Problems with an easing movieclip

I created a movieclip that follows the mouse up and down with easing, using this code:

onClipEvent (load) {
_y = 400;
speed = 5;
}
onClipEvent (enterFrame) {
endY = _root._ymouse;
_y += (endY-_y)/speed;
}

what happens is that when I load the page the movieclip goes to where the mouse is right away, before i even put the mouse over the frame. u can check it out at www.freewebs.com/flaskauf
it’s a thing for school and im just testing the menu.

how do I get the movieclip to stay at the bottom of the frame until I move the mouse over it?