PHP session entry-level function description 3

Session application example
The following examples are for reference only. You can customize or not customize the session.
(1) used for User Authentication
<? Php
Session_start ();
$ Dbh = mysql_connect ("localhost: 3306", "xxxx", "xxxx ");
Mysql_select_db ("znsoft"); // select a database
$ Query = "selectuseridfromreguserwhereuserid = $ useridandpass = $ pass ";
// $ Userid $ pass is the user name and password passed by the login form
$ Res = mysql_query ($ query, $ dbh );
If ($ row = mysql_fetch ($ res ))
{
$ Reguser = $ row [0];
?>
<Script>
Alert ("OK, buddy, welcome! ");
</Script>
<? Php
} Else {
$ Reguser = "";
?>
<Script>
Alert ("sorry, you are not a registered user! ");
</Script>
<? Php // put the code on your own
}
Session_register ("reguser ");
?>

Check whether you have logged on to the other page
======================
<? Php
Session_start ();
If (isset ($ reguser) & $ reguser! = "") // You have logged on
{
Echo "Welcome, buddy ";
} Else {// No Logon
Echo "register now ";
}
?>

Exit
====================================
<? Php
Session_destroy ();
// Or $ reguser = "";
?>


(2) used to pass variables
This program is used to pass variables between pages
<? Php
$ Name = "m. y ";
If (! Sesion_is_registered ("name") // The session variable name is not registered.
Session_register ("name"); // register the variable name
?>

Page 2
==============================
<? Php
Echo $ name;
// You don't want to use it anymore. Delete it.
If (session_is_registered ("name") // whether to register, if you have already registered
Session_unregister ("name"); // delete it of course
?>