Thanks for your tip.
Unfortunately, the pointer doesn't send to server.
Yesterday I tried another way, it worked but still have some problems.

I tested the code by a host and two clients.
In the first time, three players enter the game in sequence,
and all players can click each other and get correct health.
But when a client leaves the game and enter again, he can't click anyone anymore.
In other words, his click can't trigger the enable_click event.
I thinks it's because the new client can't get others' pointer,
so I have to resend all the entity pointers.
The problem is : How to resend pointer so that the new client can receive?
Can someone help me? Thanks very much.

My new code is as following :
Code:

---

entity* ent_you;

panel pan_show
{
	pos_x = 500;
	pos_y = 0;
	digits = 20, 10, 5, _a4font,1,ent_you.health;
	layer = 20;
	flags = refresh, d3d;
}


action move_player1  //three player actions, I just paste one
{
	actor = 1;
	wait(1);
	proc_client(my,move_player_local);
	
	if(connection == 3) 
	{
		move_player_local();
	}
}


function move_player_local()
{
	player_move();
}

function player_events()
{
	if(event_type == event_click)
	{
		ent_you = me;
		pan_show.visible = on; 
	}
	// client disconnected
	if (EVENT_TYPE == EVENT_DISCONNECT)
	{
		ent_remove(me); // remove ent of player that quit
	}
}

function fun_LocalEvent()
{
	ent_you = me;
	pan_show.visible = on;
}

function fun_ClickLocal()
{
	if(connection == 2)	
	{		
		my.enable_click = on; 
		my.event = fun_LocalEvent;	
	}
}
function player_move()
{	
	my.enable_disconnect = ON; 
	my.enable_click = ON;
	my.event = player_events; 

	my.nosend_frame = on; // don't send animation
	
	sleep(.3); // this can be left at .3 no matter what
	ent_sendnow(my);
	sleep(.3); // sleep(3); // high latency solution for now

	 proc_local(my,fun_ClickLocal);	
          
	if(actor == 1)
	{
		my.health = 50;
	}
	if(actor == 2)
	{
		my.health = 40;
	}
	if(actor == 3)
	{
		my.health = 30;
	}
	send_skill(my.health,send_all); 

	while(1)
	{
             ......//movement code
        }
}

---