Index: /trunk/FACT++/src/root2csv.cc
===================================================================
--- /trunk/FACT++/src/root2csv.cc	(revision 19815)
+++ /trunk/FACT++/src/root2csv.cc	(revision 19816)
@@ -113,4 +113,9 @@
         "   --add.Area='TMath::TwoPi()*Width*Length'\n"
         "\n"
+#if ROOT_VERSION_CODE < ROOT_VERSION(6,00,00)
+        "Note that functions which require two arguments (e.g. atan2) can be used in "
+        "a column (i.e. with --add) but can not be references in an alias.\n"
+        "\n"
+#endif
         "Sometimes leaf names might be quite unconvenient like MTime.fTime.fMilliSec or "
         "just MHillas.fWidth. To allow to simplify column names, regular expressions "
@@ -205,5 +210,5 @@
         {
             cerr << "File '" << path << "' is not writable." << endl;
-            return 7;
+            return 8;
         }
 
@@ -211,5 +216,5 @@
         {
             cerr << "File '" << path << "' already exists." << endl;
-            return 8;
+            return 9;
         }
         else
@@ -518,4 +523,13 @@
         const string val  = conf.Get<string>(*it);
 
+#if ROOT_VERSION_CODE < ROOT_VERSION(6,00,00)
+        if (val.find_first_of(',')!=string::npos)
+        {
+            cerr << "\nERROR - Alias contains comma... functions with two arguments do not work as alias in root 5!\n";
+            cerr << "   " << name << " = " << val << endl;
+            return 2;
+        }
+#endif
+
         if (verbose>0)
             cout << "Alias: " << name << " = " << val << endl;
@@ -525,5 +539,5 @@
             cerr << "\nERROR - Alias could not be established!\n";
             cerr << "   " << name << " = " << val << endl;
-            return 2;
+            return 3;
         }
     }
@@ -540,5 +554,5 @@
     {
         cerr << "Compilation of Selector failed!" << endl;
-        return 3;
+        return 4;
     }
     selector.SetQuickLoad(kTRUE);
@@ -565,5 +579,5 @@
         {
             cerr << "Compilation of Column failed!" << endl;
-            return 4;
+            return 5;
         }
         form->SetQuickLoad(kTRUE);
@@ -597,5 +611,5 @@
         {
             cerr << "Failed to enable branch '" << L->GetName() << "' (type unknown)" << endl;
-            return 5;
+            return 6;
         }
 
@@ -604,5 +618,5 @@
         {
             cerr << "Failed to enable branch '" << L->GetName() << "' (strange array size)" << endl;
-            return 6;
+            return 7;
         }