ReleaseDC

var tab=15,old_WndProc;
var pns=new TPaintStruct();

// Главная форма
frm=new TForm();
frm.Caption="JS+ - функция WinAPI ReleaseDC";
frm.Width =450;
frm.Height=300;

old_WndProc=GetWindowLong(frm.Handle,GWL_WNDPROC);
frm.WindowProc=new_WndProc;

frm.ShowModal();

// Оконная процедура главной формы
function new_WndProc(Sender,Msg,wParam,lParam)
{
  var hDC;
  var hWnd=Sender.Handle;
  var out_str="Текст выведен функцией WinAPI TextOut";

  switch (Msg) {
    case WM_PAINT : hDC=GetDC(hWnd);
                     BeginPaint(hWnd,pns);
                     SetBkColor(hDC,clLtGray.toRGB());
                     TextOut(hDC,tab,tab,out_str,out_str.length);
                     EndPaint(hWnd,pns);
                     ReleaseDC(hWnd,hDC);
                     return 0;

    case WM_DESTROY: SetWindowLong(hWnd,GWL_WNDPROC,old_WndProc);
  }

  return CallWindowProc(old_WndProc,hWnd,Msg,wParam,lParam);
}