diff --git a/demo.cpp b/demo.cpp
index 76677bf..fe01ea5 100644
--- a/demo.cpp
+++ b/demo.cpp
@@ -17,6 +17,13 @@ int main(int argc, char const *argv[])
 	if (argc < 2)
 	{
 		std::cerr << "Usage: ./tin <config-file>\n";
+		std::cerr << "Options:\n";
+		std::cerr << "grid-file = <filename>\n";
+		std::cerr << "grid-para = <xmin>/<dx>/<xmax>/<ymin>/<dy>/<ymax>\n";
+		std::cerr << "maxi-error = <value > 0>\n";
+		std::cerr << "log-file = <filename> (optional)\n";
+		std::cerr << "neighbor-file = <filename> (optional)\n";
+		std::cerr << "single-z = yes|no\n";
 		return -1;
 	}
 	
diff --git a/tin b/tin
index bf8272c..f7ff42b 100755
Binary files a/tin and b/tin differ