You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I have already booked my ticket to Houston but due to an emergency, I would like to change my reservation.

ASSISTANT: May I know your name please?

USER: My name is Melissa Nelson.

ASSISTANT: I have found your reservation, may I know your new trip dates?

USER: I will be travelling on dates from 10/19 to 10/21.

ASSISTANT: Please provide your airport codes.

USER: The airport codes are OAK and DEN.

ASSISTANT: There is a flight available for you with 1 connection. Shall I proceed?

USER: Yes, please proceed.

ASSISTANT: Your ticket is booked.

USER: Thank you for your help.

ASSISTANT: Most welcome.