1. History of mild persistent asthma symptoms (on average greater than 2 days per week with symptoms or albuterol use for symptoms or greater than 2 night-time awakenings per month during the year prior to study entry) and has been treated with a single-controller inhaled corticosteroid (ICS) dose less than or equal to 160 mcg per day of a beclomethasone-equivalent or a leukotriene receptor antagonist (LTRA) (in an age-appropriate dose) for the 4 weeks prior to study entry; individuals treated with a combination controller therapy (e.g. ICS+LTRA or ICS+long-acting beta-agonist (LABA)) in the past 8 weeks will not be eligible