Thanks alot. I found instructions here :
http://www.ehow.com/i/#article_2265355 ( I'm an impatient person and thought I'd have a look on google)
Apparently there's a video link but as I'm using an iPod I couldn't see the full site. And no link to a video. I tried to follow the instructions but it's not the same as the link you have given me. Your link makes it look alot more secure than my attempt! I'll definately use it on the next one.
Thanks again