The requirements for HK visa are as follows:
1. A completed Visa Application Form-- ID(E)1003 --, which should be typed and signed by the applicant. Visitors for tourism and business are required to submit page A, page A to be continued, and page B, C, D, L.
2. A copy (A-4 size) of the passport and U.A.E. residence visa, both of which should be valid for more than six months and a photograph as in the passport.
3. An employment/no-objection letter from the company, which clarifies the applicant's full name, position, nationality, passport number and the purpose of the visit, and a copy of the trade license, if self-employed.
4. An invitation letter from the sponsor in Hong Kong (for business visit).
5. Detailed schedule, confirmed hotel reservation and round air ticket booking (for tourism).
6. Original personal bank statement for the last three months.

I would like to ask what are the requirements to get a visa to china ,i am afghan living in dubai i have employed visa dubai,i want to go vist exibhition 15-10-2010

It is the same as what Mr.Joe reply to Mr.Kumar above. But you need to use their rush service for visa processing.