New Mac user - Help I can't find the Option button

Apologies, but I am a new user to Mac's having used pcs for the last 20 years.
I am trying to empty the trash can, but I am getting a message telling me that my files are locked and I must press the option button when I press 'empty'. Seems easy enough instructions, except I can't seem to recognise the Option key. I've tried most on the keyboard. I'm using a new MacBook Pro with Leopard.

It's the one with 'Option' printed on it. Next to the 'Open Apple' key, to the left of the space bar. It also has 'alt' printed above 'option'

Welcome to Mac-Forums, Maz.

Look at this Wikipedia entry, there is a photo of one of the Option key incarnations.

Hope this helps.