function ubb2xhtml($ubb)
{
$flash=<<<END
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
 codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,0,0" width="%1$d" height="%2$d">
 <param name="movie" value="%3$s" />
 <param name="quality" value="high" />
 <embed src="%3$s" width="%1$d" height="%2$d" quality="high" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer"></embed>
</object>
END;
 $match = array
 (
  '%[url=([^s]+)](.*?)[/url]%s',
  '%[email=([^s])+](.*?)[/email]%i',
  '%[img width=(d+) height=(d+)](.*?)[/img]%s',
  '%[img=([^s]+)/]%s',
  '%[flash width=(d+) height=(d+)](.*?)[/flash]%se',
  '%[(b|i|u|strike|sup|sub)](.*?)[/1]%s',
  '%[h([1-6])](.*?)[/h1]%s',
  '%[hr/]%s',
  '%[color=([^s]+)](.*?)[/color]%s',
  '%[font=([^"]+)](.*?)[/font]%s',
  '%[size=([^s]+)](.*?)[/size]%s',
  '%[align=(center|right|left)](.*?)[/align]%s',
  '%[valign=(middle|top|bottom)](.*?)[/valign]%s',
/*
  '%[ul](.*?)[/ul]%s',
  '%[ul=(circle|disc|square)](.*?)[/ul]%s',
  '%[ol](.*?)[/ol]%s',
  '%[ol type=([aAiI1]) start=([a-zA-Z1-9])](.*?)[/ol]%s',
  '%[li](.*?)[/li]%s',
*/
  '%[table=([^s]+?)](.*?)[/table]%s',
  '%[caption](.*?)[/caption]%s',
  '%[tr=([^s]+?)](.*?)[/tr]%s',
  '%[th](.*?)[/th]%s',
  '%[td](.*?)[/td]%s',
  '%[note](.*?)[/note]%s',
  '%[quote=(.*?)](.*?)[/quote]%s',
  '%[code](.*?)[/code]%s',
  '%[ ]{2}%s',  // make double-spaces truly double-spaces!
 );
    $replace = array
 (
  '<a href="1" target="_blank">2</a>',
  '<a href="mailto:1" target="_blank">2</a>',
  '<img src="3" width="1" height="2" border="0" />',
  '<img src="1" border="0" />',
  'sprintf("$flash", "1", "2", "3")',
  '<1>2</1>',
  '<h1>2</h1>',
  '<hr>n',
  '<font color="1">2</font>',
  '<font face="1">2</font>',
  '<font size="1">2</font>',
  '<div align="1">2</font>',
  '<div valign="1">2</font>',
/*
  '<ul>1</ul>',
  '<ul type="1">2</ul>',
  '<ol>1</ol>',
  '<ol type="1" start="2">3</ol>',
  '<li>1</li>',
*/
  "<table class="$1" cellspacing="1">n$2</table>",
  "t<caption>$1</caption>n",
  "t<tr class="$1">n$2t</tr>n",
  "tt<th>$1</th>n",
  "tt<td>$1</td>n",
  '<div class="note"><span class="hint">发布者备注</span><hr />1</div>',
  '<div class="quote"><span class="hint">引用</span>(来源: <a href="1" target="_blank">1</a>)<br />2</div>',
  '<span class="hint" style="margin-left: 10px">代码</span><div class="code">1</div>',
  '&nbsp; ',
 );
 if( preg_match('%[table=(.*?)/table]%s', $ubb, $tablecells) ) //如果有表格, 先去除单元格之间的多余空白
 {
  $bb=preg_replace('%]([rns]*)[%si', '][', $tablecells[1]);
  $ubb=str_replace($tablecells[1], $bb, $ubb);
 }
 $html = preg_replace($match, $replace, nl2br(htmlspecialchars($ubb)));
 $html = preg_replace('/<br />s*<(td|th|tr|table|ul|ol|li)/m', "n".'<1', $html);
 return $html;
}