1 files changed, 11 insertions, 0 deletions
diff --git a/logic/score.go b/logic/score.go
index 65eac12..8f518ea 100644
--- a/logic/score.go
+++ b/logic/score.go
@@ -105,3 +105,14 @@ func (s *Score) Insert(d Dices, pos int) (int, error) {
 	}
 	return 0, errors.New("Already recorded")
 }
+
+func (s *Score) Cancel(pos int) error {
+	if pos < 0 || pos > 12 {
+		return errors.New("Index out of range")
+	}
+	if s.values[pos] == 0 {
+		s.values[pos] = -1
+		return nil
+	}
+	return errors.New("Already recorded")
+}