I'm trying to redirect users of a web page to one of two different pages, depending on which of two buttons they click. My approach was to link each onclick event to a javascript function, which would in turn call a php function which uses the header() function to redirect to the appropriate page. Unfortunately, the latter of the two php functions, namely insertIntoTable(), is being called automatically each time the page loads and redirecting, without giving the user a chance to even look at the page with the buttons. I'm wondering if this is an artifact of way PHP is expanded? I don't really understand, becauseit seems like the wrapping javascript function shouldn't be called until the onclick event listener does so, and the php functions shouldn't be called until on the the javascript functions linked to onclick do so. Here is the code...
<?php
session_start();
?>
<html>
<head>
<script>
function createATable()
{
<?php createATable(); ?>
}
function insertIntoTable()
{
<?php insertIntoTable(); ?>
}
</script>
</head>
<body>
<?php
// Define our redirection functions for button click events
function createATable()
{
header("Location: http://codd.edu/Project2/createtable.php?<?php echo htmlspecialchars(SID); ?>");*/
}
function insertIntoTable()
{
header("Location: http://codd.edu/Project2/insertintotable.php?<?php echo htmlspecialchars(SID); ?>");*/
}
// Set session variables so that we don't need to worry about whether
// we're coming from sign in or registration - if $Session['user_name']
// isn't set, we know were coming from the sign in
if (!$_SESSION['user_name'])
{
$_SESSION['user_name'] = $_POST['nametextbox'];
$_SESSION['user_psswd'] = $_POST['psswdtextbox'];
echo "<br />setting session variables";
}
echo "<br />Not setting session variables";
// If we aren't setting the session variables, then we are coming from the
// registration page, and therefore know that this isn't an admin account
$_SESSION['is_admin'] = "false";
// Connect to database
$conn = mysql_connect("localhost", "601", "23");
or die('Could not connect: ' . mysql_error());
// Open database
mysql_select_db("601", $conn)
or die('Could not find database: ' . mysql_error());
// Get USER tuples, if any
$user = mysql_query("SELECT * FROM USERS WHERE name='$_SESSION[user_name]' AND password='$_SESSION[user_psswd]'");
// If there are no entries for this SELECT command, we cannot
// allow the user to log in
$num_user = mysql_num_rows($user);
if ($num_user < 1)
{
$_SESSION['is_user'] = "false";
header("Location: http://codd.edu/Project2/login.php?<?php echo htmlspecialchars(SID); ?>");
exit;
}
else
{
$_SESSION['user_id'] = SID;
$_SESSION['is_user'] = "true";
echo "Welcome ", $_SESSION['user_name'], "!";
echo "<br />User ID: " . $_SESSION['user_id'];
echo "<br /> User Password: " . $_SESSION['user_psswd'];
echo "Is valid user? " . $_SESSION['is_user'];
session_destroy();
echo "<button name='createtable' onclick='createATable()'>Create a Table</button>";
echo "<br /><button name='insert' onclick='insertIntoTable()'>Insert into Table</button>";
}
?>
</body>
</html>
