set up proxy for chromium on awesome

I use chromium on awesome and my os is arch64. Because of the GFW, I have to setup proxy so that I can surf the Internet smoothly. Here's the way:

1. (temp way) type the below command in your terminal:
auto_proxy="file:///path/to/your/proxy/pac" chromium-browser
2. (permenant way)
export auto_proxy="file:///path/to/your/proxy/pac" in $HOME/.profile

then you can surf the Internet out of the GFW.

P.S. you can use the pac generated by http://autoproxy2pac.appspot.com/. Thank autoproxy for the contribution.