1. ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details 1) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Stock-based compensation in the form of employee stock options and ESPP shares included in:
Total stock-based compensation	$ 601	$ 709	$ 947
Effect on net loss per share, Basic	$ 0.06	$ 0.08	$ 0.11
Effect on net loss per share, Diluted	$ 0.06	$ 0.08	$ 0.11
Cost Of Sales
Stock-based compensation in the form of employee stock options and ESPP shares included in:
Total stock-based compensation	36	87	108
Selling, General and Administrative
Stock-based compensation in the form of employee stock options and ESPP shares included in:
Total stock-based compensation	446	430	488
Research And Development
Stock-based compensation in the form of employee stock options and ESPP shares included in:
Total stock-based compensation	$ 119	$ 192	$ 351