Drawnow problems with consecutive windows popping out

I have a 3-dimensional matrix called "kk". As I want to see how the matrix propagates with respect to its third dimension (time), I have used the following code: for j = 1:1001 surf(xx,yy,kk(:,:,j)) drawnow end However, I have only received windows being popped out after I have closed the previous ones, instead of a series of animation on the figure window. Anything that I did wrong?