PHP strtoupper() and strtolower() in Flex

Having been a PHP programmer for many years and only now in the last month started to learn Flex and ActionScript I find I'm always looking for ways to get something done in ActionScript which I know how to do in PHP. These are pretty straight forward and simple functions but sometimes it's nice to have a reference.

PHP strtoupper( $string ) and strtolower( $string ) in Flex

public function strtoupper( str:String ):void
{
 return str.toUpperCase();
}   
public function strtolower( str:String ):void
{
 return str.toLowerCase();
}