<qa>  What is the beta-2 adrenergic receptor gene?The purpose of this trial is to determine whether regularly scheduled use of an inhaled long-acting beta agonist salmeterol in the setting of concomitant use of inhaled corticosteroids beclomethasone hydroflouroalkane HFA inhaler will have a detrimental effect on asthma control in people who bear the B16-ArgArg genotype of the beta-2 adrenergic receptor gene, as compared to people with asthma of similar severity who bear the B16-GlyGly genotype. 