whatsThis hotkeys for a Mac?

[wconstan]

Qt Creator 1.2.94
Qt 4.6.0 (32 bit)
Mac OS X 10.5.8 (Leopard)
Macbook Pro

I have defined the whatsThis property of a QPushButton. The help says that Shift+F1 is the typical set of keystrokes used to invoke the whatsThis help if the focus is on the relevant widget in the application. For a Macbook, however, the Shift+F1 key is reserved (by default) for another operation. Does anyone know what keystrokes I can press on a Mackbook to show the whatsThis content for a particular widget without having to explicitly remap my keyboard?

Thanks!