PhP error with MySql Query

<?php
$db_host = 'localhost'; // don't forget to change 
$db_user = 'user'; 
$db_pwd = 'password';
$database = 'gallery';
$table = 'Gall';
// use the same name as SQL table
$password = '123';
// simple upload restriction,
// to disallow uploading to everyone
if (!mysql_connect($db_host, $db_user, $db_pwd))
 die("Can't connect to database");
if (!mysql_select_db($database))
 die("Can't select database");
// This function makes usage of
// $_GET, $_POST, etc... variables
// completly safe in SQL queries
function sql_safe($s)
{
    if (get_magic_quotes_gpc()) $s = stripslashes($s);
    return mysql_real_escape_string($s);
    }
// If user pressed submit in one of the forms
if ($_SERVER['REQUEST_METHOD'] == 'POST')
{
    // cleaning title field
    $title = trim(sql_safe($_POST['title']));
    if ($title == '') // if title is not set
        $title = '(empty title)'; // use (empty title) string
    if ($_POST['password'] != $password)  // cheking passwors
        $msg = 'Error: wrong upload password';
    else
    {
        if (isset($_FILES['photo']))
        {
            @list(, , $imtype, ) = getimagesize($_FILES['photo']['tmp_name']);
            // Get image type.
            // We use @ to omit errors
            if ($imtype == 3) // cheking image type
                $ext="png";   // to use it later in HTTP headers
            elseif ($imtype == 2)
                $ext="jpeg";
            elseif ($imtype == 1)
                $ext="gif";
            else
                $msg = 'Error: unknown file format';
            if (!isset($msg)) // If there was no error
            {
                $data = file_get_contents($_FILES['photo']['tmp_name']);
                $data = mysql_real_escape_string($data);
                // Preparing data to be used in MySQL query
                mysql_query("INSERT INTO {$table} SET ext='$ext', title='$title', data='$data'");
                $msg = 'Success: image uploaded';
            }
        }
        elseif (isset($_GET['title'])) // isset(..title) needed
            $msg = 'Error: file not loaded';// to make sure we've using
                                            // upload form, not form
                                            // for deletion
        if (isset($_POST['del'])) // If used selected some photo to delete
        {                         // in 'uploaded images form';
            $id = intval($_POST['del']);
            mysql_query("DELETE FROM {$table} WHERE id=$id");
            $msg = 'Photo deleted';
         }
    }
}
elseif (isset($_GET['show']))
{
    $id = intval($_GET['show']);
    $result = mysql_query("SELECT ext,  UNIX_TIMESTAMP(image_time), data FROM {$table} WHERE id=$id LIMIT 1");
    if (mysql_num_rows($result) == 0) 
    die('no image');
    list($ext, $image_time, $data) = mysql_fetch_row($result);
    $send_304 = false;
    if (php_sapi_name() == 'apache') 
    {
        // if our web server is apache
        // we get check HTTP
        // If-Modified-Since header
        // and do not send image
        // if there is a cached version
        $ar = apache_request_headers();
        if (isset($ar['If-Modified-Since']) && // If-Modified-Since should exists
            ($ar['If-Modified-Since'] != '') && // not empty
            (strtotime($ar['If-Modified-Since']) >= $image_time)) 
            $send_304 = true;                   
    }
        if ($send_304)
    {
        // Sending 304 response to browser
        // "Browser, your cached version of image is OK
        // we're not sending anything new to you"
        header('Last-Modified: '.gmdate('D, d M Y H:i:s', $ts).'GMT', true, 304);
        exit(); // bye-bye
    }
    // outputing Last-Modified header
    header('Last-Modified: '.gmdate('D, d M Y H:i:s', $image_time).'GMT', true, 200);
    // Set expiration time +1 year
    // We do not have any photo re-uploading
    // so, browser may cache this photo for quite a long time
    header('Expires: '.gmdate('D, d M Y H:i:s',  $image_time + 86400*365).'GMT', true, 200);
    // outputing HTTP headers
    header('Content-Length: '.strlen($data));
    header("Content-type: image/{$ext}");
    // outputing image
    //echo $data;
    exit();
    }
?>
<html><head>
<title>MySQL Blob Image Gallery Example</title>
</head>
<body>
<?php
if (isset($msg)) // this is special section for
                 // outputing message
{
?>
<p style="font-weight: bold;"><?=$msg?>
<br>
<a href="<?=$PHP_SELF?>">reload page</a>
</p>
<?php
}
?>
<h1>Phot Gallery</h1>
<h2>Uploaded photos:</h2>
<form action="<?=$PHP_SELF?>" method="post">
<!-- This form is used for image deletion -->
<?php
$result = mysql_query("SELECT id, image_time, title FROM {$table} ORDER BY id DESC");
if (mysql_num_rows($result) == 0) // table is empty
    echo '<ul><li>No images loaded</li></ul>';
else
{
    echo '<ul>';
    while(list($id, $image_time, $title) = mysql_fetch_row($result))
    {
        // outputing list
        echo "<li><input type='radio' name='del' value='{$id}'>";
        echo "<a href='{$PHP_SELF}?show={$id}'>{$title}</a> &ndash; ";
        echo "<small>{$image_time}</small></li>";
    }
    echo '</ul>';
    echo '<label for="password">Password:</label><br>';
    echo '<input type="password" name="password" id="password"><br><br>';
    echo '<input type="submit" value="Delete selected">';
}
?>
</form>
<h2>Upload new image:</h2>
<form action="<?=$PHP_SELF?>" method="POST" enctype="multipart/form-data">
<label for="title">Title:</label><br>
<input type="text" name="title" id="title" size="64"><br><br>
<label for="photo">Photo:</label><br>
<input type="file" name="photo" id="photo"><br><br>
<label for="password">Password:</label><br>
<input type="password" name="password" id="password"><br><br>
<input type="submit" value="upload">
</form>
</body>
</html>