How to sort a matrix in a random order?

>> x = reshape(1:24,4,6)
x =
     1     5     9    13    17    21
     2     6    10    14    18    22
     3     7    11    15    19    23
     4     8    12    16    20    24
>> x(:) = x(randperm(numel(x)))
x =
     7    12     3    19    16    23
    20    24    10    11     1    17
    21    14     8     5    13    18
     6    22    15     4     2     9