Insert this in your code  

} 

view top_view 
{ 
layer = 15; 
pos_x = 0; 
pos_y = 0; 
size_x = 200; 
size_y = 150; 
tilt = -90; 
arc = 80; 
} 

starter init_topcam() 
{ 
while (player == null) {wait (1);} 
while (1) 
{ 
if (key_t == 1) 
{ 
while (key_t == 1) {wait (1);} 
if (top_view.visible == on) 
{ 
top_view.visible = off; 
} 
else 
{ 
top_view.visible = on; 
} 
} 
top_view.x = player.x; 
top_view.y = player.y; 
top_view.z = 1000; // play with this value 
wait (1); 
} 
}