While pop star Avril Lavigne has not yet finished touring in support of her latest album, "Goodbye Lullaby," she already has apparently written eight songs for a fifth album.  When asked by her fansite Avril Lavigne Band Aids about a new album this week, Lavigne replied: "I already have eight songs! I would like to release the fifth album really quick."She added: "This record was more mellow, and the next one will be pop and more fun again. I already have a song that I know is going to be a single, I just need to re-record it!"  The singer also revealed that she will be doing a cover of the Coldplay song "Fix It" as part of her current tour.  The singer will play Londons Hammersmith Apollo on September 21 and Manchesters Apollo on September 23. The dates are in support of her fourth album Goodbye Lullaby and will be her first UK shows since 2008.