preg_replace variables

[ashley98860615]

Hi, im making a bbcode editor and am using the below code to replace the tags entered. the values come from a database where i store them as:

id, name, code, type, replacement

where a standard bold would be:
#, bold, b, 1, <strong>$1</strong>

and a double url would be:
#, url, url, 2, <a href='$1'>$2</a>

the type defines wether there are two variables in the replacement. in the code below single variable replacements work but doubles don't. when using links the variable $1 is repeated for both (e.g.: <a href='$1'>$1</a>). any ideas why?

function formatbb($bbcontent) {
	$bbcontent = str_replace('<', '&lt;', $bbcontent);
	$bbcontent = str_replace('>', '&gt;', $bbcontent);
	$bbcontent = str_replace('<br />', "\n", $bbcontent);
	$sql = mysql_query("SELECT * FROM bbcodes ORDER BY id ASC") or die("Cannot get codes: ".mysql_error());
	$i = 0;
	while($patterns = mysql_fetch_array($sql)) {
		if($patterns['type'] == '1') {
			$pattern[$i] = "|\[".$patterns['code']."\](.*?)\[/".$patterns['code']."\]|s";
			$replacement[$i] = $patterns['replacement'];
		} else {
			$pattern[$i] = "|\[".$patterns['code']."=(.*?)\](.*?)\[/".$patterns['code']."\]|s";
			echo $pattern[$i]."<br />";
			$replacement[$i] = $patterns['replacement'];
		}
		$i++;
	}
	$bbcontent = preg_replace($pattern, $replacement, $bbcontent); 
	return $bbcontent;
}