1 files changed, 1 insertions, 0 deletions
diff --git a/TODO b/TODO
index b0a4d16..ded2f9b 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,6 @@
 - Add Help->About
 - Add confirm dialgs on Quit and New
+- Mark invalid input
 
 - [VERIFY] Have the options in the Move menu call validate() before solving.
 - [VERIFY] Incorporate validate() into the menu