diff -r bc3a4c498eb2 -r cfc26d103bcf src/demo/lp_demo.cc
--- a/src/demo/lp_demo.cc	Fri Apr 08 06:33:11 2005 +0000
+++ b/src/demo/lp_demo.cc	Fri Apr 08 06:34:34 2005 +0000
@@ -37,10 +37,10 @@
     for(OutEdgeIt e(g,t);e!=INVALID;++e) ex-=x[e];
     lp.setObj(ex);
   }
-
+  lp.max();
   lp.solve();
 
-  return 0;
+  return lp.primalValue();
 }
 
 int main() 
@@ -48,14 +48,19 @@
   LpGlpk lp_glpk;
 
   ListGraph g;
-  ListGraph::Node s=g.addNode();
-  ListGraph::Node t=g.addNode();
+  ListGraph::Node s;
+  ListGraph::Node t;
+  
 
   ListGraph::EdgeMap<double> cap(g);
   
   GraphReader<ListGraph> reader(std::cin,g);
-  reader.addEdgeMap("capacity",cap).run();
+  reader.addNode("source",s).addNode("target",t)
+    .addEdgeMap("capacity",cap).run();
   
-  maxFlow(g,cap,s,t);
+  // std::ifstream file("../test/preflow_");
+//   readDimacs(file, g, cap, s, t);
+
+  std::cout << "Max flow value = " << maxFlow(g,cap,s,t) << std::endl;
 
 }