Error in trapz in MatLab

I get an error "Error in trapz (line 42)

perm = [dim:max(ndims(y),dim) 1:dim-1];" for the code

J = trapz(t, y(:, 2) + y(:, 3) + y(:, 4) + y(:, 5) + K/2*u.^2);

[Torsten]

Check whether the sizes of t, y(:,2) (e.g.) and u are equal.