A YouTube video to cheer up a Watford eight-year-old in hospital undergoing chemotherapy and a bone marrow transplant has become an internet sensation.
Brooke Cornwell is one of just 125 people across the UK who has Diamond Blackfan Anaemia, a disorder which means her bone marrow cannot produce enough red blood cells to carry oxygen around her body.
The six minute 28 second film features her friends, classmates and teacher dancing around Cassiobury Park to Pharrell Williams "Happy" song.
About 60 people went to the park to do a Happy dance for Brooke, which was filmed and then put online by family friend Raymond Murphy.
The video has been an instant hit and received more than 1,000 views in the first 24 hours.
Ray said Brooke is fighting like a champion and he hoped the cheerful video would put a smile on her face.
He said: "Brooke Cornwell is an amazing girl. Without going into too much detail, she has suffered more than most people would in their lifetime.
"She is currently in hospital undergoing chemotherapy and a bone marrow transplant.
"Although she has suffered, she has really fought the fight like a champion.
"Her friends have missed her while in hospital so we decided to create a video for Brooke to let her know we're thinking of her and to put a smile on her face."
Brooke's mum Amber said her daughter loved the video.
Amber, of Breakspeare Close, said: "She watches it at least ten times a day. It's really cheered her up.
"She's been in hospital for six weeks now, but she's doing very well."
The video features groups of children, some dressed in superhero costumes, performing short dance routines and mouthing the words to the song.
Scenes were also filmed in Brooke’s classroom, with her classmates and teachers nodding and clapping in time to the song’s memorable beat.
Since it was posted on Ray’s YouTube page on Friday, May 2, the clip has received nearly 1,500 views.
Jessica Roberts commented: "Prefer this to the original video! Well done guys! Love it!"
Another commenter added: "Awesome!"
Last year Brooke was thrilled when Harry Styles from One Direction sent her a personal video message.
Mum Amber said it "made her year" when she saw the greeting wishing her lots of love from the pop heartthrob.
In December six bars and clubs around Watford invited patrons to have a drink for Brooke.
Walkabout, Yates, No.77, Reflex, Molloys and Que Pasa opened their doors and set up donation boxes to raise money for the brave eight-year-old.
The donation details are on Brooke's website on the donation page: http://bravebrookecornwell.weebly.com/index.html.