Here is a copy of ours. Code:
function FindProxyForURL(url, host)
{
//Declare proxy strings as variables
var capitaproxy = "PROXY 10.112.5.193:80";
// IP not to use proxy
if (shExpMatch(url, "*172.*")) { return "DIRECT"; }
if (shExpMatch(url, "*10.*")) { return "DIRECT"; }
if (shExpMatch(url, "*192.*")) { return "DIRECT"; }
if (shExpMatch(url, "*127.0.0.1*")) { return "DIRECT"; }
if (isPlainHostName(host)) { return "DIRECT"; }
// URLS not to use proxy server
if (shExpMatch(url, "*webmail.school.com*")) { return "DIRECT"; }
// Slect Proxy Server
if (isInNet(myIpAddress(), "172.16.4.0", "255.255.252.0")) { return capitaproxy; }
if (isInNet(myIpAddress(), "172.16.128.0", "255.255.252.0")) { return capitaproxy; }
if (isInNet(myIpAddress(), "172.16.140.0", "255.255.255.0")) { return capitaproxy; }
if (isInNet(myIpAddress(), "172.16.141.0", "255.255.255.0")) { return capitaproxy; }
else
return "DIRECT";
}