Adding an attachment in iOS mail app and another question

Hello all,
If I reply to a message using the iOS mail app how do I add an attachment? I tried this earlier and could find no way to do it. Also if I am in the body of the message editing it, how do I dismiss the keyboard? I tried using the scrub gesture and all it did was back me out of the reply and send me back to the message I was replying to.

Thanks,
Greg Wocher