7. EQUITY COMPENSATION PLANS (Details - Share based compensation) (USD $)	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Share based compensation	$ 1,776,000	$ 1,593,000
Cost of contract manufacturing
Share based compensation	24,000	24,000
Research and development
Share based compensation	743,000	741,000
Selling, general and administrative
Share based compensation	1,009,000	828,000
Stock Options
Share based compensation	1,697,000	1,503,000
Employee Stock Purchase Plan
Share based compensation	$ 79,000	$ 90,000