Wie kann man eine View Entity anklicken?

// example needs:
// backgr1.tga = 1024x768 background image
// backgr2.tga = same
// door1.tga   = a door image
// door2.tga   = same
// cursor.tga  = mouse cursor
BMAP* bmap_arrow = "cursor.tga"; // mouse cursor bitmap

ENTITY* your_background;         // pointer to your used background image 1024x768 in this example
ENTITY* your_door_ent;           // pointer to your door image (any size)


void your_background_ent_event_1(){ // first example event for your background
   if (event_type == EVENT_CLICK){
      printf ("You clicked the background");
   }			
}
void your_background_ent_event_2(){ // second example event for your background room 2
   if (event_type == EVENT_CLICK){
      printf ("You clicked the background in room2");
   }			
}


void your_door_ent_event_1(){      // first example event for your door
   if (event_type == EVENT_CLICK){
      printf ("You clicked the door entity");
   }			
}
void your_door_ent_event_2(){      // second example event for your door in room2
   if (event_type == EVENT_CLICK){
      printf ("You clicked the door entity in room2");
   }			
}

// load the background and the door and give them click events
void init_level_screen1(){
   your_background = ent_create ("backgr1.tga", vector (880,0,0), NULL); // 1024x768 background image for example fills screen at this position
   if (your_background){
      your_background.emask |= ENABLE_CLICK;
      your_background.event = your_background_ent_event_1;
   }	
   your_door_ent = ent_create ("door1.tga", vector (879,0,0), NULL); // in front of the background image
   if (your_door_ent){
      your_door_ent.emask |= ENABLE_CLICK;  
      your_door_ent.event = your_door_ent_event_1;	     
   }
} 

// example how you could switch to another room
void init_next_room (roomnr){
    if (roomnr == 2){
       if (your_background){
          ent_morph (your_background, "backgr2.tga");		
	  your_background.event = your_background_ent_event_2;
      }
      if (your_door_ent){
         //your_door_ent.y = 100;
         //your_door_ent.z = 50;
         ent_morph (your_door_ent, "door2.tga");		
         your_door_ent.event = your_door_ent_event_2;
      }
   }
}

var room_active = 1;

// press enter to switch to room nr2 for example
void main(){ 
   video_mode = 7;
   video_screen = 2;
   level_load (NULL); // or a empty wmb file
  
   init_level_screen1();
    
   mouse_map = bmap_arrow;  
   mouse_mode = 4;       
  
   while (1){
      if (key_enter){
         if (room_active == 1){
            room_active += 1;
            init_next_room (room_active); //change background and the door image for next room now           
         }
      }	
      wait (1);
   }
}