Michael Douglas: 'Courtesy is key to a successful marriage'

Michael Douglas has opened up about the secret to his happy marriage of nearly 19 years.

The 74-year-old is happier than ever with his other half, actress Catherine Zeta-Jones. And while the pair have one of the longest-lasting marriages in Hollywood, Michael believes the key to a content relationship is being courteous with one another.

"I think it just comes out of courtesy," Michael told Us Weekly. "You know, I think sometimes we take the person closest to us for granted. I would say sometimes we make more of an effort with strangers than we do with the person who's closest to us. And I've always tried to remember how fortunate I am and what an extraordinary lady she is and daily remember (of) that kind of respect."

Michael and Catherine, 49, have also always done their best to sort out their issues as and when they pop up.

Explaining it's a good idea to "talk things out", the Wall Street star added: "It's taken me a long time but resentment is an easy thing to keep under the surface. I think most of the times it's really good to get things out sooner than later."