up()
{
llSetBuoyancy(1.2);
}

down()
{
llSetBuoyancy(0.8);
}

stay_still()
{
llSetBuoyancy(1.0);
}

default
{
    state_entry()
    {
        llRequestPermissions(llGetOwner(), PERMISSION_TAKE_CONTROLS);
        llSetBuoyancy(1.0);
    }

    run_time_permissions(integer perm)
    {
        if(PERMISSION_TAKE_CONTROLS & perm)
        llTakeControls(CONTROL_UP | CONTROL_DOWN, TRUE,FALSE);
    }
    control(key id, integer level, integer edge)
    {
        integer held = level & ~edge;
        integer released = ~level & edge;
        if(held & CONTROL_UP)
        {
            up();
        }
        if(held & CONTROL_DOWN)
        {
            down();
        }
        if (released)
        {
            stay_still();
        }
    }
}