function nls2p($str) {
	$str = str_replace('<p></p>', '', '<p>'
        . preg_replace('#([
]\s*?[
]){2,}#', '</p><p>', $str)
        . '</p>');
	return $str;
}

Turns /n to <br> and /n/n to </p><p>

Usage:
echo stripslashes(nl2br(nls2p($text)));

Convert new lines to paragraphs

format

PHP