How to make a movie clip repel the cursor

Hi, having trouble with this .fla (attached) i have an object on the stage and I want to be able to make it repel the mouse cursor, similar to a magnet, so you cant get near it…

The MC is called BOX and this code I have on the frame…

var dist = 30;
var objx = box._x += (box._width/2);
var objy = box._y += (box._height/2);

if(_xmouse > (objx -= dist) && _xmouse < (objx += dist) && _ymouse > (objy -= dist) && _ymouse < (objy += dist)) {
box._x = Math.ceil(Math.random() * Stage.width;
box._y = Math.ceil(Math.random() * Stage.height;

But doesn’t seem to work… Any help much appreciated.