SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity - $ / shares	12 Months Ended
	May. 31, 2015	May. 31, 2014
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, number of options (in Shares)	356,000
Options exercised, number of options (in Shares)	23,000	69,000
Price Range Per Share $0.38-$0.75 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013 (in Shares)		846,500
Options outstanding at May 31, 2013		$ 0.47
Price Range Per Share $0.71-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, number of options (in Shares)		178,000
Options granted, price per share		$ 0.75
Price Range Per Share $0.38-$0.60 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, number of options (in Shares)		(69,000)
Options exercised, price per share		$ 0.51
Price Range Per Share $0.43-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, number of options (in Shares)		(95,000)
Options canceled or expired, price per share		$ 0.59
Price Range Per Share $0.38-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013 (in Shares)	860,500
Options outstanding at May 31, 2013	$ 0.51
Options outstanding, number of options (in Shares)		860,500
Options outstanding, price per share		$ 0.51
Price Range Per Share $0.82-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, number of options (in Shares)	356,000
Options granted, price per share	$ 0.82
Price Range Per Share $0.38-$0.71 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, number of options (in Shares)	(23,000)
Options exercised, price per share	$ 0.42
Price Range Per Share $0.43-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, number of options (in Shares)	(45,500)
Options canceled or expired, price per share	$ 0.72
Price Range Per Share $0.38-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding, number of options (in Shares)	1,148,000
Options outstanding, price per share	$ 0.60
Minimum [Member] | Price Range Per Share $0.38-$0.75 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013		0.38
Minimum [Member] | Price Range Per Share $0.71-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, price per share		0.71
Minimum [Member] | Price Range Per Share $0.38-$0.60 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, price per share		0.38
Minimum [Member] | Price Range Per Share $0.43-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, price per share		0.43
Minimum [Member] | Price Range Per Share $0.38-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013	0.38
Options outstanding, price per share		0.38
Minimum [Member] | Price Range Per Share $0.82-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, price per share	0.82
Minimum [Member] | Price Range Per Share $0.38-$0.71 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, price per share	0.38
Minimum [Member] | Price Range Per Share $0.43-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, price per share	0.43
Minimum [Member] | Price Range Per Share $0.38-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding, price per share	0.38
Maximum [Member] | Price Range Per Share $0.38-$0.75 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013		0.75
Maximum [Member] | Price Range Per Share $0.71-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, price per share		0.84
Maximum [Member] | Price Range Per Share $0.38-$0.60 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, price per share		0.60
Maximum [Member] | Price Range Per Share $0.43-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, price per share		0.84
Maximum [Member] | Price Range Per Share $0.38-$0.84 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding at May 31, 2013	0.84
Options outstanding, price per share		$ 0.84
Maximum [Member] | Price Range Per Share $0.82-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options granted, price per share	0.85
Maximum [Member] | Price Range Per Share $0.38-$0.71 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options exercised, price per share	0.71
Maximum [Member] | Price Range Per Share $0.43-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options canceled or expired, price per share	0.85
Maximum [Member] | Price Range Per Share $0.38-$0.85 [Member]
SHAREHOLDERS' EQUITY (Details) - Outstanding Stock Options Activity [Line Items]
Options outstanding, price per share	$ 0.85