2 files changed, 27 insertions, 2 deletions
diff --git a/logic/score.go b/logic/score.go
index af6eefc..d65bb7c 100644
--- a/logic/score.go
+++ b/logic/score.go
@@ -129,8 +129,8 @@ func (s_ *Score) Cancel(pos int) error {
 	if pos < 0 || pos > 12 {
 		return errors.New("Index out of range")
 	}
-	if s[pos] == 0 {
-		s[pos] = -1
+	if s[pos] == -1 {
+		s[pos] = 0
 		return nil
 	}
 	return errors.New("Already recorded")
diff --git a/logic/score_test.go b/logic/score_test.go
index 4fe0000..11a460c 100644
--- a/logic/score_test.go
+++ b/logic/score_test.go
@@ -111,3 +111,28 @@ func TestInsert(t *testing.T) {
 		t.Errorf("Inserting %v at index 200 should fail", d)
 	}
 }
+
+func TestCancel(t *testing.T) {
+	s := NewScore()
+	
+	err := s.Cancel(1)
+	if err != nil {
+		t.Errorf("Cancelling Aces should not fail: %v", err)
+	}
+	
+	err = s.Cancel(1)
+	if err == nil {
+		t.Errorf("Cancelling Aces twice should fail")
+	}
+	
+	err = s.Cancel(12)
+	if err != nil {
+		t.Errorf("Cancelling Yahtzee should not fail: %v", err)
+	}
+	
+	err = s.Cancel(22)
+	if err == nil {
+		t.Errorf("Cancelling 22 should fail")
+	}
+
+}