Hilton HHonors - So where do I enroll?

Today's e-mail:

"This fall, stay any Friday and/or Saturday night at a Hilton Garden Inn®, pay with an eligible, enrolled American Express® Card at time of reservation and earn 1,000 Membership Rewards Bonus Points."

Perhaps my bifocals are tripping me up, but I don't see a link for enrolling.

Thoughts?

Today's e-mail:

"This fall, stay any Friday and/or Saturday night at a Hilton Garden Inn®, pay with an eligible, enrolled American Express® Card at time of reservation and earn 1,000 Membership Rewards Bonus Points."

Perhaps my bifocals are tripping me up, but I don't see a link for enrolling.

Thoughts?

AmEx Membership Rewards program requires enrollment, no? ;)

http://www.membershiprewards.com/HomePage.aspx

Offer Valid 11/4/2009 - 12/16/2009
This fall, stay any Friday or Saturday night at Hilton Garden Inn from 11/4/09-12/15/09, pay with an eligible, enrolled American Express® Card at time of reservation and check-in and earn 1,000 Membership Rewards® Bonus Points. Chose from close to 500 Hilton Garden Inns Worldwide!

TO EARN...
Book your stay online at HGI.com and use offer code REWARD. To learn more, visit www.HGI.com/AMEX.