1:
2:
3:
4:
5:
6:
7:
8:
9:

interface
function SetHook(WinHandle: HWND; MsgToSend: Integer): Boolean; stdcall; external 'GlobalKeyHook.dll';
function FreeHook: Boolean; stdcall; external 'GlobalKeyHook.dll';
(...)
implementation
procedure Form.StarteHook;
begin
  SetHook(Handle, WM_USER + 300);
end;                    

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:

interface 
type
  FunctionSetHook = function(WinHandle: HWND; MsgToSend: Integer): Boolean;
var
  funcSetHook: FunctionSetHook;
(...)
implementation
procedure Form.StarteHook;
var
  b: boolean;
  hKeyboardHook: THandle;
begin
  if FileExists('GlobalKeyHook.dll') then
  begin
    hKeyboardHook:= LoadLibrary('GlobalKeyHook.dll');
    if hKeyboardHook > 0 then
    begin
      @funcSetHook:= GetProcAddress(hKeyboardHook, 'SetHook');
      b:= false;
      if Assigned(funcSetHook) then
        b:= funcSetHook(Handle, WM_USER + 300);
      if not b then
      begin
        ShowMessage(GetErrorString(GetLastError));
        FreeLibrary(hKeyboardHook);
        hKeyboardHook:= 0;
      end;      
    end;
  end;
end;