diff --git a/pigeon_magnet_solver/board.py b/pigeon_magnet_solver/board.py
index 7d46c9a..bc63fc4 100644
--- a/pigeon_magnet_solver/board.py
+++ b/pigeon_magnet_solver/board.py
@@ -39,7 +39,7 @@ class Board:
         # check buttons
         length = self.height * self.width
         assert all(
-            button >= 0 and button < length
+            button in range(length)
             for button in self.buttons
         ), "Invalid buttons!"
 
@@ -72,5 +72,16 @@ class Board:
             for column in self.columns
         )
 
+    def __idx_to_xy(self, index: int) -> tuple[int, int]:
+        return index % self.width, index // self.width
+
+    def is_clickable(self, index: int) -> bool:
+        # check index
+        assert index in self.buttons, f"{index} is not a button!"
+
+        # check is button
+        x, y = self.__idx_to_xy(index)
+        return self.rows[y][x] == "1"
+
     def click(self, index: int) -> None:
-        pass
+        assert self.is_clickable(index), f"{index} is not clickable!"
diff --git a/tests/test_board.py b/tests/test_board.py
index 9b3c5fd..18d52e7 100644
--- a/tests/test_board.py
+++ b/tests/test_board.py
@@ -10,3 +10,8 @@ def test_default():
     assert board.columns == ("001x", "1101", "110x"), "Wrong columns"
     assert board.binary_repr == (4, 11, 3), "Wrong binary repr"
     assert board.solution_class == (1, 3, 2), "Wrong solution class"
+
+    assert board.is_clickable(3) is False, "Button 3 should be inactive"
+    assert board.is_clickable(4) is True, "Button 4 should be active"
+    assert board.is_clickable(5) is True, "Button 5 should be active"
+    assert board.is_clickable(7) is False, "Button 7 should be inactive"