AMSTERDAM (Reuters) - Dutch brewer Grolsch is doing its best to put some fizz into the national anthem, by printing the lyrics on up to three million beer cans. "We want people to be able to sing along with the (national song) Wilhelmus, and with our can in their hands, they should be able to do so," Grolsch spokesman Paul Koenings told Reuters. The Dutch are proud of their country but few know the Wilhelmus by heart. Grolsch wants to change that. The first cans arrived in the shops last week, timed to coincide with two big national holidays - Queen`s Day on April 30 and Liberation Day on May 5.