Need bubbles be fart by crab

Hello, here is my question, i have bubbles coming out when spacebar is pressed and crab instructed to follow my mouse. I want these bubbles be “farted” by crab, so to be connected to his position.
i tried this:

        _root["bubbleTOP1" + i]._x = _root.KANITOP._x;
        _root["bubbleTOP1" + i]._y = _root.KANITOP._y;

but it only connects bubbles at the begining.

Please help me to solve this, im very beginner with AC and im confused:asian:

EDIT01: ehm, and i forgot, KANITOP is instance name of crab and bubbleTOP1 is identifier of bubble because i attaching it from library