Sniffing out dollar bills used to fuel drug wars

We all know that money talks - but apparently it smells too. Chemists in the United States have captured the scent of a dollar bill and it will be used by machines to sniff out cash being smuggled over the border to Mexico. Each year, billions of dollars filter into Mexico to pay for the drug habits of Americans and Homeland security wants to be able to stem the flow of cash. The BBC's James Morgan has been following the story.