+As of 0.010 hwnd can also be C<"active"> to capture the active (or
+"foreground") window.
+
+=item screenshot hwnd => 0
+
+Retrieve a screeshot of the default desktop under Win32.
+
+=item screenshot hwnd => 0, display => -1
+
+Retrieve a screenshot of all attached monitors under Win32.
+
+Note: this returns an image with an alpha channel, since there can be
+regions in the bounding rectangle of all monitors that no particular
+monitor covers.
+
+=item screenshot hwnd => 0, display => I<index>
+
+Retrieve a screenshot from a particular monitor under Win32. A
+I<display> of zero is always treated as the primary monitor.
+