what does othello vow at the end of act 3 scene 3? what does iago pledge to do

Othello is incensed to hear that Desdemona would give away something so valuable, and is persuaded by Iago's insinuations and claims to believe that Desdemona is guilty. Othello then swears to have Cassio dead, and to be revenged upon Desdemona for the non-existent affair.