1. To begin with, make a flash document. Set the size to 300×300 pixels.

Place on the root stage a movie clip.

Go to Insert -> New symbol -> Movie Clip, name it haircross.

With the line tool, draw a cross:

2. Drag&Drop the movie clip from the library (windows -> Library) on to the main stage, and give the movie clip an instance name: mc1.

3. Now, place the following script in the first frame of the main stage:

speed = .9;
setInterval(CursorMovement, 40);
function CursorMovement() {
mc1._x = speed*(mc1._x-_xmouse)+_xmouse;
mc1._y = speed*(mc1._y-_ymouse)+_ymouse;
}