turn based system: ds_list_delete is messed up

[31Nf4ChZ4H73N]

I am working on a turn based game. the order of the turns is stored in a ds_list. Sometimes the code is executed a coupple of times even though I only pressed the mouse_button once. I'm working with child objects of the battle unit. does anyone have an idea whats wrong? is it the code or what? Thank you guys in advance

///Step code of the battle_unit
if(state == wait_state)
{
    if(mouse_check_button_released(mb_left))
    {
        next_turn();
    }
}

///next_turn script
ds_list_delete(o_battle.turn_list,0);
if(ds_list_size(o_battle.turn_list) >0)
{
    with(o_battle_unit)
    {
        state = idle_state;
    }
    with(o_battle.turn_list[| 0]) // o_battle.turn_list[| 0] gives back the object id
    {  
        state = wait_state;
    }
}

 

[31Nf4ChZ4H73N]

i put the next_turn script out of the battle_unit child and now it is working. but i thougt because i calling the object id from the ds_list only one object can execute the script?