function myfunction($a,$b){

			if ($a===$b){

			  return 0;

			}

		return ($a>$b)?1:-1;
	}



		$a1 = array("a"=>"red","b"=>"green","c"=>"blue");

		$a2 = array("d"=>"red","b"=>"green","e"=>"blue");

		$result = array_diff_uassoc($a1,$a2,"myfunction");

		print_r($result);