[1M1e]

like this ?

#include <amxmodx>

#define PLUGIN "ConnectDisconnect Message"
#define VERSION "1.0"
#define AUTHOR "AlliedMods"


public plugin_init() {
    register_plugin(PLUGIN, VERSION, AUTHOR)
}

public client_join(id)
{
	 set_task(2.0, "client_connect" ,ADMIN_BAN)
}

public client_connect(id){
    new szName[32]
    new szID[32]
    get_user_authid(id, szID, 19)
    get_user_name(id, szName, charsmax(szName))
    client_print(0, print_chat, "%s is connecting SteamID(%s)", szName, szID)
}

public client_joined(id)
{
	 set_task(2.0, "client_putinserver" ,ADMIN_BAN)
}

public client_putinserver(id){
    new szName[32]
    new szID[32]
    get_user_authid(id, szID, 19)
    get_user_name(id, szName, charsmax(szName))
    client_print(0, print_chat, "%s has connected SteamID(%s)", szName, szID)
}

public client_left(id)
{
	 set_task(2.0, "client_disconnected" ,ADMIN_BAN)
}  

public client_disconnected(id){
    new szName[32]
    new szID[32]
    get_user_authid(id, szID, 19)
    get_user_name(id, szName, charsmax(szName))
    client_print(0, print_chat, "%s has disconnected SteamID(%s)", szName, szID)
}

not work