The Sunbrella - an umbrella which keeps you warm as well as dry - was the winning invention at a competition for school pupils styled on the BBC television show Dragons' Den.

Gosford Hill School in Kidlington beat off competition from runners-up at The Cherwell School, in Oxford, who invented a light bulb which changes colour when it is about to blow.

Another team from The Cherwell School, called Swan Organics, received a highly commended certificate for their business idea - selling organic smoothies at school. The competition, part of the Business of Enterprise Programme, was organised by the Education Business Partnership.

It is part of a Government drive to encourage young people to be more enterprising.

The county final was held at Thame on Friday and also involved The Marlborough School, in Woodstock.

Each team had to give a five-minute presentation of their design to a panel of judges and answer questions on their business plans.

Sunbrella's team - Rahul Bali, Josh Mair, Hatty Barrett and Emily Blay - have won a trip to the Fox FM radio studios for their gadget and will go through to the regional final next month. The runners-up will celebrate with a free meal.

Fiona Clarke, senior manager of the Oxfordshire Education Business Partnership, said: "All students in the year group take part, working together to develop key skills such as creativity, teamwork, problem-solving and decision-making."