Forum:Re-Attack (?) Query

I couldn't find this ruling anywhere in the rules section of this website and I am very curious about it. Let's say I attack a beast type monster with a monster I control on the field, the opponent chains "Horn of The Phantom Beast". Must I go through with my attack? Or can I choose to not attack? What about quick play spells like Book of Moon? Please help. Thanks

76.29.17.210 (talk) 03:25, August 13, 2011 (UTC)