Ant and Dec present the fourth night of the live semi-finals as more acts take to the stage in a bid to impress Simon Cowell, Alesha Dixon, David Walliams and Amanda Holden and reach the final on Saturday night. The winners of the show will scoop the £250,000 prize and a slot at the Royal Variety Performance and hopefully gain as much success as previous winners such as Susan Boyle, Paul Potts and Diversity.