Dermot O'Leary hosts the semi-finals. The four remaining acts - Danyl, Joe, Olly and Stacey - must perform two songs each, and it will be up to them to really sing their hearts out if they are to be in with a chance of making it to next week's final. Judges Cheryl Cole, Simon Cowell, Dannii Minogue and Louis Walsh will be crossing their fingers for their favoured acts. Who will impress the panel and the voters at home? (thetvdb.com)