Is my work permit still valid after my visitor TRV has been approved?

[MJAF]

I have a valid work permit until Oct 24th 2013. I applied for a TRV as a visitor and it has been approved and sent to me in Canada with a starting date of Sep 19th 2013. I want to know if my work permit is still valid until it's expiration of Oct 24th or if it was cancelled as soon as my visitor status was approved?

I cannot find anything on this anywhere on CIC or the forums.
Any help would be much appreciated.