preg_match_all - find alt mellem <center></center>

Jeg vil gerne finde alt mellem <center></center>

fx.:
<center>
<table width="750" align="center" cellpadding="0" cellspacing="0" class="headerborder">
  <tr>
    <td><img src="images/header.jpg"></td>
  </tr>
</table>
</center>

preg_match_all('/<center>(.*?)<\/center>/i',$tekst,$typer);