[code] case 'url':
if (!$parms) {
$url = substr($str, $epos+1, ($cpos-$epos)-1);
} else {
$url = $parms;
}

$url = url_check($url);

if (!strncasecmp($url, 'www.', 4)) {
$url = 'http://'. $url;
} else if (strpos(strtolower($url), 'javascript:') !== false) {
$ostr .= substr($str, $pos, $cepos - $pos + 1);
$epos = $cepos;
$str[$cpos] = '<';
break;
} else {
$url = str_replace('://', '://', $url);
}

$end_tag[$cpos] = '</a>';
$ostr .= '<a href="'.$url.'" target="_blank">';
break;
[/pre]

[code]case 'tex':
$url = substr($str, $epos+1, ($cpos-$epos)-1);
$end_tag[$cpos] = '';
$ostr .= '<img src="/cgi-bin/mimetex.cgi?'.$url.'">';

Another Try

case 'tex':
$end_tag[$cpos] = '--';
$ostr .= '<img src="/cgi-bin/mimetex.cgi?'.substr($str, $epos+1, ($cpos-$epos)-1).'">';
break;
break;[/pre]