-#define GDI_DESIGN_UNPRESSED 17
-#define GDI_DESIGN_PRESSED 18
-#define GDI_ALT_DESIGN_UNPRESSED 19
-#define GDI_ALT_DESIGN_PRESSED 20
-#define GDI_BORDER_SIZE 21
-#define GDI_TEXTINPUT_DESIGN_WIDTH 22
-#define GDI_DECORATION_DESIGN 23
-#define GDI_DECORATION_POSITION 24
-#define GDI_DECORATION_SIZE 25
-#define GDI_DECORATION_SHIFTING 26
-#define GDI_EVENT_MASK 27
-#define GDI_EVENT 28
-#define GDI_CALLBACK_INFO 29
-#define GDI_CALLBACK_ACTION 30
-#define GDI_AREA_SIZE 31
-#define GDI_ITEM_SIZE 32
-#define GDI_SCROLLBAR_ITEMS_MAX 33
-#define GDI_SCROLLBAR_ITEMS_VISIBLE 34
-#define GDI_SCROLLBAR_ITEM_POSITION 35
-#define GDI_INFO_TEXT 36
+#define GDI_SELECTBOX_VALUES 17
+#define GDI_SELECTBOX_INDEX 18
+#define GDI_DESIGN_UNPRESSED 19
+#define GDI_DESIGN_PRESSED 20
+#define GDI_ALT_DESIGN_UNPRESSED 21
+#define GDI_ALT_DESIGN_PRESSED 22
+#define GDI_BORDER_SIZE 23
+#define GDI_BORDER_SIZE_SELECTBUTTON 24
+#define GDI_TEXTINPUT_DESIGN_WIDTH 25
+#define GDI_DECORATION_DESIGN 26
+#define GDI_DECORATION_POSITION 27
+#define GDI_DECORATION_SIZE 28
+#define GDI_DECORATION_SHIFTING 29
+#define GDI_EVENT_MASK 30
+#define GDI_EVENT 31
+#define GDI_CALLBACK_INFO 32
+#define GDI_CALLBACK_ACTION 33
+#define GDI_AREA_SIZE 34
+#define GDI_ITEM_SIZE 35
+#define GDI_SCROLLBAR_ITEMS_MAX 36
+#define GDI_SCROLLBAR_ITEMS_VISIBLE 37
+#define GDI_SCROLLBAR_ITEM_POSITION 38
+#define GDI_INFO_TEXT 39