PHP 自定义错误问题

目前，我有以下代码：

<?php
if (isset($_GET['s'])) {
    $itemid = $_GET['s'];
    $search = "$itemid";
    $query  = ucwords($search);
    echo "<title>Results for $query</title>";
    $string = file_get_contents('http://clubpenguincheatsnow.com/tools/newitemdatabase/items.php');
    if ($itemid == "") {
        echo "Please fill out the form.";
    } else {
        echo '<div id="content">';
        $string = explode('<br>', $string);
        foreach ($string as $row) {
            preg_match('/^(.+)'s='s('d+)'s='s('D+)'s='s('d+)/', trim($row), $matches);
            if (preg_match("/$query/i", "$matches[1]")) {
                echo "<a href='http://clubpenguincheatsnow.com/tools/newitemdatabase/info.php?id=$matches[2]'>";
                echo $matches[1];
                echo "</a><br>";
            }
        }
        echo '</div>';
    }
} else {
    echo "Item does not exist!";
}
?>

如果"$matches[1]"中没有任何内容，我希望我的代码它回显"项目不存在！不过我该怎么做呢？请帮忙！

我以前尝试过类似if ($matches[1]=="") { echo "Item does not exist!"; }的东西，但没有用。这就是我得到的：

http://img685.imageshack.us/img685/998/28990b2c12d0423292d3574.png

看到工作正常吧？看看如果$matches[1]确实存在会发生什么：

http://img528.imageshack.us/img528/3690/71472c9de6ec49118ee8d48.png

它仍然出现！如何制作我的代码，使其仅在没有$matches[1]的情况下回显错误？请帮帮我！

如果您想知道，这是我添加if ($matches[1]=="") { echo "Item does not exist!"; }时的代码：

<?php
if (isset($_GET['s'])) {
    $itemid = $_GET['s'];
    $search = "$itemid";
    $query  = ucwords($search);
    echo "<title>Results for $query</title>";
    $string = file_get_contents('http://clubpenguincheatsnow.com/tools/newitemdatabase/items.php');
    if ($itemid == "") {
        echo "Please fill out the form.";
    } else {
        echo '<div id="content">';
        $string = explode('<br>', $string);
        foreach ($string as $row) {
            preg_match('/^(.+)'s='s('d+)'s='s('D+)'s='s('d+)/', trim($row), $matches);
            if (preg_match("/$query/i", "$matches[1]")) {
                echo "<a href='http://clubpenguincheatsnow.com/tools/newitemdatabase/info.php?id=$matches[2]'>";
                echo $matches[1];
                echo "</a><br>";
            }
        }
        echo '</div>';
        if ($matches[1] == "") {
        echo "Item does not exist!";
        }
    }
} else {
    echo "Item does not exist!";
}
?>

我的问题的任何帮助将不胜感激！