Flash MX/Mouse follow

i made my guy so that he stops running when te mouse goes over him but once u put the mouse over him he keeps sliding untill the it reaches the root. and its a reaaaaally slow slide becuz of the ease. how can i make it so that it stops the sliding as soon as it hits the mc. here’s my script.

onClipEvent (load) {
_x = 0;
speed = 25;
}
onClipEvent (enterFrame) {
endX = _root._xmouse;
_x += (endX-_x)/speed;
}
on (rollOver) {
gotoAndStop(21);
}
on (rollOut) {
gotoAndPlay(1);
}