Problem with random move

1

hello there,
i have 10 pics on the stage and i need to give them random movement and swepdepth for each image when i rollover.

my problem is that the random movement stop on the start this is my code:


onClipEvent (load) {
    numOfImages = 10;
    acceleration = 10;
    ranx = new Array();
    rany = new Array();
    newpos = function (i) {
        ranx* = Math.round((Math.random()*250));
        rany* = Math.round((Math.random()*150));
    };
    for (i=1; i<(numOfImages+1); i++) {
        newpos(i);
    }
    _root.img1.onRollOver = function() {
        _root.img1.swapDepths(_root.getNextHighestDepth());
    };
    _root.img2.onRollOver = function() {
        _root.img2.swapDepths(_root.getNextHighestDepth());
    };
    _root.img3.onRollOver = function() {
        _root.img3.swapDepths(_root.getNextHighestDepth());
    };
    _root.img4.onRollOver = function() {
        _root.img4.swapDepths(_root.getNextHighestDepth());
    };
    _root.img5.onRollOver = function() {
        _root.img5.swapDepths(_root.getNextHighestDepth());
    };
    _root.img6.onRollOver = function() {
        _root.img6.swapDepths(_root.getNextHighestDepth());
    };
    _root.img7.onRollOver = function() {
        _root.img7.swapDepths(_root.getNextHighestDepth());
    };
    _root.img8.onRollOver = function() {
        _root.img8.swapDepths(_root.getNextHighestDepth());
    };
    _root.img9.onRollOver = function() {
        _root.img9.swapDepths(_root.getNextHighestDepth());
    };
    _root.img10.onRollOver = function() {
        _root.img10.swapDepths(_root.getNextHighestDepth());
    };
}

onClipEvent (enterFrame) {
    for (i=1; i<(numOfImages+1); i++) {
        _root['img'+i]._x += ((ranx*-_root['img'+i]._x)/acceleration);
        _root['img'+i]._y += ((rany*-_root['img'+i]._y)/acceleration);
        if (Math.round(_root['img'+i]._x) == ranx* || Math.round(_root['img'+i]._y) == rany*) {
            newpos(i);
        }
    }
}