diff --git a/docs/tutorial/LangImpl2.html b/docs/tutorial/LangImpl2.html
index 50619e0..018d0be 100644
--- a/docs/tutorial/LangImpl2.html
+++ b/docs/tutorial/LangImpl2.html
@@ -337,7 +337,7 @@
       if (CurTok == ')') break;
     
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
@@ -1007,7 +1007,7 @@
       if (CurTok == ')') break;
     
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
diff --git a/docs/tutorial/LangImpl3.html b/docs/tutorial/LangImpl3.html
index 28b9dac..47e1783 100644
--- a/docs/tutorial/LangImpl3.html
+++ b/docs/tutorial/LangImpl3.html
@@ -881,7 +881,7 @@
       if (CurTok == ')') break;
     
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
diff --git a/docs/tutorial/LangImpl4.html b/docs/tutorial/LangImpl4.html
index 41b58c7..999c194 100644
--- a/docs/tutorial/LangImpl4.html
+++ b/docs/tutorial/LangImpl4.html
@@ -714,7 +714,7 @@
       if (CurTok == ')') break;
     
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
diff --git a/docs/tutorial/LangImpl5.html b/docs/tutorial/LangImpl5.html
index 8081fc3..ae53fd9 100644
--- a/docs/tutorial/LangImpl5.html
+++ b/docs/tutorial/LangImpl5.html
@@ -1137,7 +1137,7 @@
       if (CurTok == ')') break;
       
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
diff --git a/docs/tutorial/LangImpl6.html b/docs/tutorial/LangImpl6.html
index 1f159e0..6059ad0 100644
--- a/docs/tutorial/LangImpl6.html
+++ b/docs/tutorial/LangImpl6.html
@@ -1085,7 +1085,7 @@
       if (CurTok == ')') break;
       
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }
diff --git a/docs/tutorial/LangImpl7.html b/docs/tutorial/LangImpl7.html
index 6d82fa9..fc8f130 100644
--- a/docs/tutorial/LangImpl7.html
+++ b/docs/tutorial/LangImpl7.html
@@ -1286,7 +1286,7 @@
       if (CurTok == ')') break;
       
       if (CurTok != ',')
-        return Error("Expected ')'");
+        return Error("Expected ')' or ',' in argument list");
       getNextToken();
     }
   }