Banking facilities (Details 1) (USD $)	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Banking Facilities Details 1
Amount utilized Hong Kong dollars	$ 3,814,000	$ 1,870,000

Represents gains or losses resulting from transactions conducted in foreign currencies.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 830

-SubTopic 20

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6939497&loc=d3e30226-110892

Name:	us-gaap_ConversionGainsAndLossesOnForeignInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration