Best wishes for 2011!!

We would like to take a bus from Beijing to Chengde (the hours of the train do not suit us). We have read that there are some "direct" buses that take only 2,5 hours. Is this correct? Could you please let us know from which bus station these buses depart and at which frequeny? How can you recognise the direct buses (color, name of the company, ...)? Can you just show up without reservation?

Thank you very much for your help!