php string as id not working code example

Example: php make text id attribute safe

function seoUrl($string) {
		//Lower case everything
		$string = strtolower($string);
		//Make alphanumeric (removes all other characters)
		$string = preg_replace("/[^a-z0-9_\s-]/", "", $string);
		//Clean up multiple dashes or whitespaces
		$string = preg_replace("/[\s-]+/", " ", $string);
		//Convert whitespaces and underscore to dash
		$string = preg_replace("/[\s_]/", "-", $string);
		return $string;
	}