% st = tk_busy_cancel (text)
%
% tk_busy_cancel(text) sets up an hourglass box with the text message
% inside and a cancel button. While in your processing loop you should
% periodically test whether the cancel button has been pressed by calling
% without arguments. After your loop, you should call tk_busy_cancel
% without arguments and without a return value. You may update the
% message within the loop by calling tk_busy_cancel with a new text
% string.
%
% Example
% tk_busy_cancel('Counting...');
% for i=1:100000
% if (tk_busy_cancel) break; end
% if (mod(i,100)==0)
% tk_busy_cancel(sprintf('Counting... %d',i));
% end
% end
% tk_busy_cancel;
% printf('Counted to %d\n', i);