Redirection upon payment completion

I am wanting to redirect a customer upon payment completion to BOTH the order confirmation page and also an external (Facebook) page on a separate tab or window.
I am trying to increase sales by getting people to like and also shop through Facebook.

I think this is more of a HTML than a Zencart thing and have searched through the site but cannot find an answer.

Most people get highly annoyed when they are "forced" through a re-direct to look at something they did not choose to. not only does it confuse them (how did I get here?) but it also creates a feeling that some unwanted behaviour is being forced into their browser.

Invite people to go elsewhere through above-board and honest means.

I agree with Schoolboy. It would be better to simply add some text and a like button link to the order confirmation page.