Redirect on _blank popup link

[sleepy]

Hello, I am creating a service which users can gain access to after clicking an advertisement link (The advertiser knows and agrees that this is OK). My objective is to use PHP to display the code that runs the advert. When a user clicks the advert, it loads in a popup (or pop under), and the main page forwards to a new address where the actual service is.

 

So here's a simple flow diagram:

 

Load page > Click advert link > Automatically redirected to content...
                        V
                Advert pops up

 

Also, I will need to incorporate a login script such that the user must log in before moving to the advertiser link page, however I can probably accomplish that with a pre existing script. Could anyone take the time to guide me through the script I would need for the above advertising system to work?

 

Thanks!