Love him or hate him, but Nicholas Sparks has the success of over 50 million books sold behind him. Seven of his novels have been made into movies. The latest, "The Lucky One", starring Zac Efron, is coming out April 20th.

How do you write a successful love story? According to Nicholas Sparks, you have to know how old the characters are. “Age informs dilemma. If you’re going to write a novel about everlasting love, the characters can’t be teenagers,” Sparks says.

Ask yourself "what if?". No dilemma for the lead equals no story.

Make concrete decisions. “I have to know the age of the characters, I’ve got to know how they meet. I have to know the conflict that’s keeping them apart and what brings them together. Finally, I have to know how it ends,” he says. And for him, there are only three endings: “happy, sad or bittersweet.”

Make sure it isn't cheesy. “You don’t want to be cliché or melodramatic, and you want it to evoke genuine emotion, and that’s tough,” Sparks says.

Wanna be a part of the next Nicholas Sparks novel?

He's written the title, "The End of All Things", the opening line, " Jasmine Blake thought she understood what love meant until the day she almost died," and the last line, "She was just falling asleep when the car stopped, and Rick whispered, 'We're home.'"

What goes in between is up to you! Here's where you can get involved.