Added the button states as returned by IsDlgButtonChecked().
diff --git a/include/winuser.h b/include/winuser.h
index 51d98ba..8a1c5ed 100644
--- a/include/winuser.h
+++ b/include/winuser.h
@@ -1273,6 +1273,13 @@
#define BN_DISABLE 4
#define BN_DOUBLECLICKED 5
+/* Button states */
+#define BST_UNCHECKED 0x0000
+#define BST_CHECKED 0x0001
+#define BST_INDETERMINATE 0x0002
+#define BST_PUSHED 0x0004
+#define BST_FOCUS 0x0008
+
/* Static Control Styles */
#define SS_LEFT 0x00000000L
#define SS_CENTER 0x00000001L