Помогите пожалуйста исправить ошибку в PHP коде

<?php

$error = false;

if(isset($_GET['date']) and strlen($_GET['date']) > 3) {
    $date = $_GET['date'];
} else {
    $error = true;
}

if (!$error) {
    $date_start = $date.' 00:00:00';
    $date_end = $date.'  23:59:59';
    $res = mysql_query("SELECT information_items_id, information_systems_id, information_items_date, information_items_name, information_items_url
            FROM information_items_table
            WHERE information_items_date > '$date_start' AND information_items_date < '$date_end'
            ORDER BY information_items_id DESC
            LIMIT 99") or die(mysql_error());
    $total = mysql_num_rows($res);
}

if (($total > 0) && (!$error)) {
    echo "<p><b>Найдено событий: $total</b></p><ol>";

    while ($row = mysql_fetch_array($res)) {
        $item_id = $row['information_items_id'];
        $system_id = $row['information_systems_id'];
        $item_date = $row['information_items_date'];
        $item_name = $row['information_items_name'];
        $item_url = $row['information_items_url'];

        $res2 = mysql_query("SELECT structure_id, information_systems_name
            FROM information_systems_table
            WHERE information_systems_id = '$system_id' AND site_id = 2
            LIMIT 1") or die(mysql_error());

        $row2 = mysql_fetch_array($res2);
        $structure_id = $row2['structure_id'];
        $system_name = $row2['information_systems_name'];

        $res3 = mysql_query("SELECT structure_path_name
            FROM structure_table
            WHERE structure_id = '$structure_id'
            LIMIT 1") or die(mysql_error());

        $row3 = mysql_fetch_array($res3);
        $structure_path = $row['structure_path_name'];

        if (strlen($item_url) > 0) {
            $this_url = $item_url;
        } else {
            $this_url = $item_id;
        }

        echo '<li style="padding-bottom:10px;"><a href="/'.$structure_path.'/'.$this_url.'/">'.$item_name.'</a> (<a href="/'.$structure_path.'/">'.$system_name.'</a>)</li>';
    }

    echo "</ol>";

} else {
    echo 'За указанный период событий не найдено.';
}

?>