Commitments and contingencies (Tables)

12 Months Ended

Mar. 31, 2014

Commitments And Contingencies Disclosure [Abstract]

Operating Lease Expenses Included in Determination of Net Income [Table Text Block]

Operating lease expense that has been included in the determination of the net income is as follows:

	Years ended March 31,
	2012		2013		2014
	US$		US$		US$
Office premises		778,364		726,893		700,402
Residential apartments for employees		102,725		104,557		81,308
Total operating lease expense		881,089		831,450		781,710

Schedule Of Future Minimum Rental Payments For Operating Leases Table [Text Block]

The minimum annual lease commitments under the above operating leases that have initial or remaining terms in excess of one year are as follows:

For the year ending March 31,	US$
2015		525,791
2016		308,732
2017		231,058
2018		237,989
2019		40,753