HWND pascal FindWindow(char *szClassName, char *szWindowName)

  This function searches for a window of the given class who has the
window text szWindowName.

Parameters
  szClassName is the name of a predefined or user-defined class.
  szWindowName is the window title or text.

Returns
  The handle of the found window, or NULLHWND is no matching window
was located.

Example

HWND hOKButton;
hOKButton = FindWindow("PushButton", "OK");