3. Reversibility of Disease: Patients must have at least 15% reversibility (all patients) and at least a 200 mL increase from baseline FEV1 (patients age 18 and older) within 30 minutes after 2 to 4 inhalations of albuterol/salbutamol at the SV. Note: Patients who do not qualify for the study due to failure to meet reversibility will be permitted to perform a retest once within 7 days.