Moving multiple items using onEnterFrame

I am trying create to move objects (boxes, named box_1, box_2 etc) to positions on the stage (xPos_1, xPos_2 etc) using onEnterFrames. I can make all the boxes move individually, but I cant get them to move together. I am using the following code in an attempt to move 3 boxes.

If anyone can point me in the right direction it would be appreciated!


while (k < 3) {

_root.onEnterFrame = function() {
    
        _root["box_"+k]._x -= 5;
        _root["box_"+k]._y -= 5;
        
        if (_root["box_"+k]._x <= _root["xPos_"+k]) {
            _root["box_"+k]._x = _root["xPos_"+k];
        }
        
        if (_root["box_"+k]._y <= yPos) {
            _root["box_"+k]._y = yPos;
        }
    
    }
k++;    
}