About php session applet_PHP tutorial

//Login page (login.php3)
//This script is used to enter the password for the user and determine whether the password is correct.
//If correct, go to the welcome page.
if ($login){
include("../include/config.inc.php3");
session_start();
$right_enter=0;
$query=" select * from user_define where user_login=$user_login and user_pass=password($user_pass)";
$result=@mysql_query($query,$dbconnect);
if ($user_array=@mysql_fetch_array($result)) {
$user_id=$user_array[user_id];
$user_name=$user_array[user_info];
session_register("user_id");
session_register("user_name");
session_register( "user_array");
if(($user_array[ticket_day]) and ($user_array[ticket_num])){
$right_enter=1;
}
else{
$error_message= "Sorry, you do not have the authority to book tickets!";
}
}
else{
$error_message="Error! Wrong username or wrong password. Please re-enter.";
}
$log_time=date("Y-m-d H:i:s");
$query="insert into log_record (log_time,user_login,remote_addr,right_enter,enter_function) values ​​($log_time,$user_login,$ REMOTE_ADDR,$right_enter,1)";