Mine

function mise_en_page($t) {
    $t = preg_replace("!\[(url|email)\](.+)\[/(?:url|email)\]!Ui","[$1=$2]$2[/$1]",$t);
	$t = preg_replace("!\[url=([^\]]+)\](.+)\[/url\]!Ui","<a href=\"$1\">$2</a>",$t);
	$t = preg_replace("!\[email=([^\]]+)\](.+)\[/email\]!Ui","<a href=\"mailto:$1\">$2</a>",$t);
	$t = preg_replace("!\[img\](.+)\[/img\]!Ui","<img src=\"$1\" alt=\"\" />",$t);
	$t = preg_replace('!\[b\](.+)\[/b\]!i', '<strong>$1</strong>', $t);
    $t = preg_replace('!\[i\](.+)\[/i\]!i', '<em>$1</em>', $t);
	$t = preg_replace("#\[php\](.*?)\[/php\]#si", '<p class="bb_php">$1</p>', $t);
	$t = preg_replace("#\[html\](.*?)\[/html\]#si", '<p class="bb_html">$1</p>', $t);
	$t = preg_replace("#\[css\](.*?)\[/css\]#si", '<p class="bb_css">$1</p>', $t);
	$t = preg_replace("#\[quote\](.*?)\[/quote\]#si", '<p class="bb_quote">$1</p>', $t);
	$t = preg_replace("`((?:https?|ftp)://\S+)(\s|\z)`", '<a href="$1">$1</a>$2', $t);
	$t = str_replace("\n","<br />",$t);
    $t = stripslashes($t);
	return $t ;
}