You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Scott Garcia.

ASSISTANT: How can I aid you today?

USER: Due to post pone of my seminar, I would like to change my existing reservation.Can you please help me in changing?

ASSISTANT: Sure, I will aid you with that. Please wait a moment, I will check your previous reservation status.

USER: Sure.

ASSISTANT: I have found your reservation. Can you please mention your preferable travel dates?

USER: My depart will be on July 19th and return on July 21st.

ASSISTANT: May I know your airport code names for further process?

USER: My airport codes are from HOU to IAD.

ASSISTANT: Do you have any another specifications?

USER: The depart time should be afternoon. I need a halt.

ASSISTANT: Ok, please wait a moment, I will check flight availability in this route.

USER: Sure.

ASSISTANT: AA airline flight available with connection limit 1 and fare is 100, shall I confirm this economy class flight?

USER: You can confirm.

ASSISTANT: Your flight ticket is booked successfully, flight number is 1010.

USER: Thank you.

ASSISTANT: You are welcome Scott Garcia.