Select the Tools menu from the menu bar, and from there Options
Click on the Advanced icon
Click on the Network tab then click on Settings
Select Automatic proxy configuration URL:
And type in the box : http://www.aston.ac.uk/proxies/internal.pac
When you have finished, if you no longer wish your Internet connection to go via Aston’s proxy, you should reset to a normal Internet connection by selecting Direct connection to the Internet.