Jada Pinkett Smith reveals the secret of her successful marriage to Will Smith.

The 42-year-old actress responded on how she had remained married to her superstar hunk of a husband, Will Smith 45; that their marriage has lasted that long because they are best friends. ‘Your partner has to be your best, best friend. And he's my best friend,' Jada told Extra at the FOX presentation for the Television Critics Association.

Jada and Smith were married in December 1997

 She also added another piece of marriage advice; ‘You have to be able to withstand tough times and just because the tough times comes doesn't mean it's time stop. It means it's time to dig in,' she added.

Jada and Will were married on December 31, 1997 and despite breakup rumours over the years they've been going strong. 'We're going to be celebrating 20 years in two years, so we're starting to plan now for a big 20th year,' she said.

The couple with their children, Willow and Jaden

The actress attended the TCA summer press tour where she talked about her role as villainess Fish Mooney on the new TV show Gotham.