Please help.. probably simple (flash 8)

Hi Everyone!

Please excuse me, im quite new to actionscript and so find myself struggling with knowing what to search for really.

While searching for some flash inspiration today, I came across this template design…

I really like the way that the circles follow the mouse to a point and then stop, I have searched all over the net for a way to do this but I dont know exactly what im looking for.

I found the Kirupa tutorial that shows a mouse follow with ease script that works almost in the way im looking for but due to my lack of AS knowledge, Im unsure how I would make the movie clip im animating stop at a certain X & Y of the stage.

Here is the code I think could be manipulated…

onClipEvent (load) {
_x = 0;
_y = 0;
speed = 5;
}
onClipEvent (enterFrame) {
endX = _root._xmouse;
endY = _root._ymouse;
_x += (endX-_x)/speed;
_y += (endY-_y)/speed;
}

Could anyone shed a little light on this?

Thankyou very much!