diff --git a/lcl/include/interfacebase.inc b/lcl/include/interfacebase.inc
index 59600d1f0e..0210c0da01 100644
--- a/lcl/include/interfacebase.inc
+++ b/lcl/include/interfacebase.inc
@@ -126,13 +126,18 @@ begin
   Result := 0;
 end;
 
-
 Function TInterfaceBase.CombineRgn(Dest, Src1, Src2 : HRGN;
   fnCombineMode : Longint) : Longint;
 begin
   Result := ERROR;
 end;
 
+function TInterfaceBase.ComboBoxDropDown(Handle: HWND;
+  DropDown: boolean): boolean;
+begin
+  Result := false;
+end;
+
 constructor TInterfaceBase.Create;
 begin
   inherited Create;
@@ -1666,6 +1671,9 @@ end;
 { =============================================================================
 
   $Log$
+  Revision 1.87  2003/04/11 17:10:20  mattias
+  added but not implemented ComboBoxDropDown
+
   Revision 1.86  2003/03/29 17:20:05  mattias
   added TMemoScrollBar
 
diff --git a/lcl/include/winapi.inc b/lcl/include/winapi.inc
index 12160a9adf..3934d05261 100644
--- a/lcl/include/winapi.inc
+++ b/lcl/include/winapi.inc
@@ -104,12 +104,16 @@ begin
   Result := InterfaceObject.ClipboardRegisterFormat(AMimeType);
 end;
 
-
 Function CombineRgn(Dest, Src1, Src2 : HRGN; fnCombineMode : Longint) : Longint;
 begin
   Result := InterfaceObject.CombineRgn(Dest, Src1, Src2, fnCombineMode);
 end;
 
+function ComboBoxDropDown(Handle: HWND; DropDown: boolean): boolean;
+begin
+  Result := InterfaceObject.ComboBoxDropDown(Handle,DropDown);
+end;
+
 function CreateBitmap(Width, Height: Integer; Planes, BitCount: Longint; BitmapBits: Pointer): HBITMAP;
 begin
   Result := InterfaceObject.CreateBitmap(Width, Height, Planes, BitCount, BitmapBits);
@@ -1580,6 +1584,9 @@ end;
 { =============================================================================
 
   $Log$
+  Revision 1.81  2003/04/11 17:10:20  mattias
+  added but not implemented ComboBoxDropDown
+
   Revision 1.80  2003/03/29 23:52:25  mattias
   IpHtmlPanel can show simple HTML pages, but there are mem bugs
 
diff --git a/lcl/include/winapih.inc b/lcl/include/winapih.inc
index 940b878a67..6eb549c82d 100644
--- a/lcl/include/winapih.inc
+++ b/lcl/include/winapih.inc
@@ -58,6 +58,7 @@ function ClipboardGetOwnerShip(ClipboardType: TClipboardType;
 function ClipboardRegisterFormat(const AMimeType: string): TClipboardFormat; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 
 Function CombineRgn(Dest, Src1, Src2 : HRGN; fnCombineMode : Longint) : Longint; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
+function ComboBoxDropDown(Handle: HWND; DropDown: boolean): boolean; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 function CreateBitmap(Width, Height: Integer; Planes, BitCount: Longint; BitmapBits: Pointer): HBITMAP; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 function CreateBrushIndirect(const LogBrush: TLogBrush): HBRUSH; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 function CreateCaret(Handle: HWND; Bitmap: hBitmap; width, Height: Integer): Boolean; {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
@@ -375,6 +376,9 @@ procedure RaiseLastOSError;
 { =============================================================================
 
   $Log$
+  Revision 1.74  2003/04/11 17:10:20  mattias
+  added but not implemented ComboBoxDropDown
+
   Revision 1.73  2003/03/29 17:20:05  mattias
   added TMemoScrollBar
 
diff --git a/lcl/interfaces/gtk/gtkwinapih.inc b/lcl/interfaces/gtk/gtkwinapih.inc
index d05a44b178..1cbfd9650b 100644
--- a/lcl/interfaces/gtk/gtkwinapih.inc
+++ b/lcl/interfaces/gtk/gtkwinapih.inc
@@ -46,6 +46,7 @@ function ClipboardGetOwnerShip(ClipboardType: TClipboardType;
 function ClipboardRegisterFormat(const AMimeType: string): TClipboardFormat; override;
 
 Function CombineRgn(Dest, Src1, Src2 : HRGN; fnCombineMode : Longint) : Longint;  override;
+function ComboBoxDropDown(Handle: HWND; DropDown: boolean): boolean; override;
 function CreateBitmap(Width, Height: Integer; Planes, BitCount: Longint; BitmapBits: Pointer): HBITMAP; override;
 function CreateBrushIndirect(const LogBrush: TLogBrush): HBRUSH; override;
 function CreateCaret(Handle : HWND; Bitmap : hBitmap; width, Height : Integer) : Boolean; override;
@@ -201,6 +202,9 @@ Procedure DeleteCriticalSection(var CritSection: TCriticalSection); Override;
 { =============================================================================
 
   $Log$
+  Revision 1.67  2003/04/11 17:10:20  mattias
+  added but not implemented ComboBoxDropDown
+
   Revision 1.66  2003/03/29 17:20:05  mattias
   added TMemoScrollBar