How to Create to Policy to give access to Internet for 1 hour only-ISA 2006

Hi,

I have two questions which are as follows.

1. how can i create a policy wherein I can give access to INTERNET to all the users for ONE HOUR only through ISA 2006.

2.how can i create a policy where in i cam give access to a particular site only to a user blocking all other sites through ISA 2006.

Thank you

Nayeem Mohammed Network Administrator