 A computer generated table of random numbers will be used to assign children to treatment group. A locked area in the ED will contain numbered plastic bags each containing either 15 mg of racemic albuterol or 7.5 mg of levalbuterol. Since we are only enrolling children 6 years of age they should all weigh 20 kg and therefore will receive 7.5 mg of racemic albuterol 0.5, 2.5mg0.5 ml Nephron Pharmaceuticals in normal saline total volume 20 ml nebulized over one hour if assigned to the albuterol group i.e. the equivalent of 2.5 mg every 20 minutes for 3 doses. If they are between 6 and 11 years of age they will receive 1.89 mg levalbuterol and if 12 years of age 3.75 mg of levalbuterol in the same volume of normal saline. This would be the equivalent of giving 3 treatments every 20 minutes for one hour. Both study medications will be identical in odor and appearance. All children will receive 2 mgkg of methylprednisolone up to a maximum dose of 60 mg orally within the first 20 minutes of treatment. All children will also receive two unit doses of ipratropium bromide 1000 mcg in the first hour of nebulization therapy as this is standard of care. 