Patients will record their symptoms on a daily basis in the morning according to "cough", "breathlessness" and "wheeze" on a 4 point scale with 0=no symptoms and 3=maximal symptoms. A total symptom score will be calculated out of 12. Patients will also measure their peak expiratory flow on a daily basis in the morning and record the highest of three measurements. They will record that they have taken their study medication.