我如何在PHP页面之间共享数据？

Question

I have a PHP page and I want to share some data between pages like UserID, password.

I'm learning about sessions and I'm not sure if Im using it correctly.

<?php
require_once('database.inc');
$kUserID = $_POST['kUserID'];
$kPassword = $_POST['kPassword'];

if (!isset($kUserID) || !isset($kPassword)) { 
    header( "Location: http://domain/index.html" ); 
}

elseif (empty($kUserID) || empty($kPassword)) { 
    header( "Location: http://domain/index.html" ); 
} 
else { 
    $user = addslashes($_POST['kUserID']); 
    $pass = md5($_POST['kPassword']); 
    $db = mysql_connect("$sHostname:$sPort", $sUsername, $sPassword) or die(mysql_error()); 
    mysql_select_db($sDatabase) or die ("Couldn't select the database."); 
    $sqlQuery = "select * from allowedUsers where UserID='" . $kUserID . "' AND passwordID='" . $kPassword . "'";
    $result=mysql_query($sqlQuery, $db);
    $rowCheck = mysql_num_rows($result); 
    if($rowCheck > 0){ 
        while($row = mysql_fetch_array($result)){
            session_start();
            session_register('kUserID'); 
            header( "Location: link.php" );
       } 
    } 
    else { 
        echo 'Incorrect login name or password. Please try again.'; 
    } 
} 
?> 

Answer 1

For the love of all that is holy, don't use addslashes to prevent SQL injection.

I just owned your site:

Image of your ownt site http://localhostr.com/files/8f996b/Screen+shot+2010-02-23+at+7.49.00+PM.png

Edit: Even worse.

I just noticed that you're attempt at preventing injection via addslashes, isn't even being used!

<?php
$kUserID = $_POST['kUserID'];
$user = addslashes($_POST['kUserID']); // this isn't used
$sqlQuery = "select * from allowedUsers where UserID='"
  . $kUserID . "' AND passwordID='" . $kPassword . "'";