Fair value of financial instruments (Narrative) (Details) (USD $)	9 Months Ended
	Oct. 31, 2012
Fair Value Of Financial Instruments 1	0
Fair Value Of Financial Instruments 2	622,138
Fair Value Of Financial Instruments 3	$ 0.02
Fair Value Of Financial Instruments 4	2,500,000
Fair Value Of Financial Instruments 5	$ 0.0264