How to have numbered Sections formatted [1] instead of standard 1?

[Gordon Watson]

How to have numbered Sections formatted [1], [2], etc., instead of standard 1, 
2, etc.?

Reason: In text, I cross-reference Equations thus --  (1), (2) -- because 
that's the way equations are numbered..

So, in text, I'd like to cross-reference Sections thus --   [1], [2], etc.

Thanks; Gordon