diff -r 142633fc5014 -r 082fc511c2b9 src/work/peter/graph-displayer.cc
--- a/src/work/peter/graph-displayer.cc	Fri Apr 01 09:44:29 2005 +0000
+++ b/src/work/peter/graph-displayer.cc	Fri Apr 01 13:42:31 2005 +0000
@@ -279,6 +279,11 @@
 
 int main(int argc, char *argv[])
 {
+  if(argc<2)
+  {
+      std::cerr << "USAGE: gd <input filename.lgf>" << endl;
+      return 0;
+  }
 
   Coordinates coosvector;
 
@@ -291,7 +296,7 @@
   CoordReaderMap xreader('x',cm);
   CoordReaderMap yreader('y',cm);
 
-  std::ifstream is("graphocska.lemon");
+  std::ifstream is(argv[1]);
 
   GraphReader<Graph> reader(is, g);
   reader.addNodeMap("coordinates_x", xreader);