Initiative 502 to legalize the recreational use of marijuana will be the subject of a special forum tomorrow night at the Capital Theater in Yakima. Former Seattle police chief Norm Stamper and former State Republican Senator George Rohrbacher will both speak in favor of the measure. The initiative would allow the sale of up to 1 ounce of marijuana from state stores to those 21 years old and  older. The state would also tax the sales. it's predicted the sale of marijuana could bring the state more than 5 hundred million dollars in new taxes every year. The forum starts at 7 tomorrow night at the Capital Theater in Yakima.