CTRL + Return = www. + .com ...how to wrap text in Firefox on Leopard?

Hi, I think it had been possible to type a word, such as Apple, in the location bar of a Firefox browser and automatically wrap it with www. and .com by typing Ctrl + Return after typing the word in the location bar.

Is this still possible in Firefox on Leopard? I seem unable to evoke this wrapping shortcut.

Thanks.