(CNN) Oprah Winfrey surprised a New Jersey high school Friday night with a pizza party -- and a $500,000 donation to an after-school program.

"That's a half a million dollars to encourage you to keep doing what you're doing, because what you're doing is moving in the right direction," Winfrey said in a video principal Akbar Cook posted on Instagram. "I saw what your great principal was doing, and I thought, what can I do?"

Winfrey posted a video on Facebook and said she "had to come see" what Cook is doing for students at West High School in Newark.

The gift was to support Cook's Lights On program. It gives the kids a safe place to gather on Friday nights. They can play basketball and video games, shoot pool and work on cheers until 11 p.m., affiliate WPVI reported. The program also will run three nights each week over the summer.

Cook also installed a laundry room at school after students were bullied for having dirty clothes and then missing class, the station said.