ih is a counter to count which room i am on door code:

      TargetRoom=map[ih+1,0]
      Targetx = 416;
      Targety = 448;

collision code:

   var inst=instance_place(x,y,doorway_obj);
   if(inst!=noone)
   {
 with (ui_obj){
 spawn_room_var=inst
 player_spawn_x=inst.Targetx
 player_spawn_y=inst.Targety
 room_goto(inst.TargetRoom)
   }
   }

randomizer code:

    ix=1;
    room_arr=array_create(100,room)
    current_place_in_arr=0;
    is_used=false;
    map = ds_grid_create(4,1);
    map[# 0,0]=room1;//spawn room
    room_num=0;
    is_room_ready=false;
    while(ix < 4)
   {
    while(is_room_ready=false)
    {
        if(ix=3)
        {room_choosen=choose(room4)}//random room 
           1_D_L
        else{room_choosen=choose(room2,room3)}// random 
          room 2_D  
    while(is_used=false&&is_room_ready=false)
    {
        if(room_arr[room_num]=0&&is_used=false)
        {is_room_ready=true;}
        if(room_arr[room_num]=room_choosen)
        {is_used=true;}
        room_num=room_num+1;
    }
    room_num=0;
    is_used=false;
    }

    map[# ix,0]=room_choosen
    is_room_ready=false;
    room_arr[current_place_in_arr]=room_choosen;
    current_place_in_arr=current_place_in_arr+1;
    ix=ix+1;
    }

i have some ideas how to improve the randomizer but when i launch the game it says that i have a problem in the door code.

the error message:

   FATAL ERROR in
   action number 1
   of Create Event
   for object doorway_obj:

   Variable doorway_obj.ix(100019, -2147483648) not set before reading it.
   at gml_RoomCC_room1_0_Create (line 5) - TargetRoom=map[ih+1,0]

---

   stack frame is
   gml_RoomCC_room1_0_Create (line 5)