I am Indian national, UAE resident. Do I need visa to Hong Kong?

I am an Indian National, I am working in Dubai and i am planning to travel Hong Kong for attending exhibition (Asia Attractions Expo 2012) from June 5 to 8 at Hong Kong Exhibition Center. Can i get visa on arrival or i should get visa prior to travel. In Dubai from where i can obtain visa, what are the requirements.

appreciate your prompt reply.

Regards,
Sivadasan