diff --git a/matlab/WriteOpenEMS.m b/matlab/WriteOpenEMS.m
index 691a0a4..d7c9cbd 100644
--- a/matlab/WriteOpenEMS.m
+++ b/matlab/WriteOpenEMS.m
@@ -1,6 +1,15 @@
 function WriteOpenEMS(filename, FDTD, CSX)
 % function WriteOpenEMS(filename, FDTD, CSX)
-% 
+%
+% Write the FDTD and CSX structures to a file.
+%
+% example:
+% CSX = InitCSX();
+% FDTD = InitFDTD();
+% WriteOpenEMS('test.xml',FDTD,CSX)
+%
+% See also InitFDTD InitCSX CSXGeomPlot
+%
 % openEMS matlab interface
 % -----------------------
 % author: Thorsten Liebig