This is a study involving a 2 week run-in phase followed by an 8 week double blind treatment phase. During the run-in phase, subjects receive Flixotide®. In the treatment phase subjects will be randomised to one of the four treatment groups and will receive either high dose FlutiForm® and Foradil® plus Flixotide® placebo or low dose FlutiForm® plus Foradil® and Flixotide® placebo or Foradil® plus Flixotide® and FlutiForm® placebo or Flixotide® and FlutiForm® plus Foradil® placebo. Efficacy will be assessed by lung function tests, asthma symptoms, sleep disturbance due to asthma and rescue medication use. Safety will be assessed by adverse events, lab tests, ECGs and vital signs.