I am planning a trip to SEA in the next couple of months. I've been looking at flights and China Southern Airways is the cheapest by far but there is a change in CAN which is an airport in China. I'll only be there a few hours to change planes but do I need visa or I'm ok as I'm just changing planes. Also I posted a previous thread about medication and could I take it into Cambodia. The answer to this is yes and I was ok last year taking my medication into Thailand with a stop over in Qatar. Please can some one let me know please.