Given the following magic square:

Fill in the magic square, in such a way that the sum of the numbers in each row (horizontally, vertically, and diagonally) is 264, even if you hold the square upside down. You are only allowed to use the digits 1, 6, 8, and 9, and each number may appear only once in the square.

The question: How should this be done?

The answer: Click here!