function AdvanceMTime

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Electromagnetic Finite-Difference Time-Domain %
% Version 1.20, Release 1                       %
%                                               %
%   (C) Copyright 2005                          %
%   Sharif University of Technology             %
%   School of Electrical Engineering            %
%   All Rights Reserved                         %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

global U Tx Ty 
global DifferenceDirection
global f1 f2 g1 g2

Sx=BlochDiff(U,1,+DifferenceDirection,0);
Sy=BlochDiff(U,2,+DifferenceDirection,0);   

Tx=f1.*Tx-f2.*Sy;
Ty=g1.*Ty+g2.*Sx;