My chinese visa which has a letter M, in the entires box.

Hi,I m a Malaysian who seldom travels to China. I will be going there again this end of May 2012. Since my Visa has a letter M, I assume this is meant to be a multi entries.It's due to expire in 01 June 2013. And my passport will be expired in Nov 2015.
From my understanding,my present visa can be used for my coming visit in may. Am I correct?
Your assistance is very much appreciated.