how to scan the image in specific region is all white?

   true
    final= maxxImage(60:100, :);
if all(final == 0)
  disp('rows were all pure white');
else 
  disp('there was at least one pixel somewhere in one of the rows that was not pure white');
end

from the maxxImage(BinaryImage),i want to find whether the value in region row(60 to 100),all columns is all white. and display the result. when its no true,its display its not pure white.

[Walter Roberson]

duplicates http://uk.mathworks.com/matlabcentral/answers/215220-how-to-check-the-value-0-in-row-200-till-240-whole-column-is-true