Intercettare caratteri in una pagina

[satifal]

$str = '
<table width="200" border="0" cellspacing="0" cellpadding="0">
<tr>
<td class="boot">id</td>
<td class="jid">001</td>
</tr>
<tr>
<td class="boot">id1</td>
<td class="jid">002</td>
</tr>
<tr>
<td class="boot">id2</td>
<td class="jid">003</td>
</tr>
<tr>
<td class="boot">id3</td>
<td class="jid">003</td>
</tr>
<tr>
<td class="boot">id4</td>
<td class="jid">004</td>
</tr>
</table>
';

$pattern = '/<td class="jid">(.*)<\/td>/i';
preg_match_all($pattern, $str, $matches);

foreach($matches[1] as $value) {
    echo $value."<br/>";
}