portico

I am a 47 yr old Canadian male. I have been working for a 5 star hotel in Phuket for the past 18 months. The Hotel's HR Dept looked after all my visa and work permit issues. I left the Phuket Hotel on Dec 5th and moved to BKK to start a new job with a different company on Dec 7th. I have a NON-Immigrant B Visa Stamp (not a decal) in my passport and the multiple entry NON-Immigrant B visa expires Dec 31, 2010. Over 1 year from now. My tourist visa has also been renewed by HR and is valid til Feb 22nd 2010. My question is, Do I have to leave the country to obtain another Non-Immigrant B Visa to start working for the new company in BKK. I have all the documents from the new company here in BKK and I have to decide if going to Laos is the right decision. I have heard many different stories and I know someone on this forum should know the correct procedure. Thank you,