You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: This is Joseph Nelson, I want to change my existing reservation. Can you help me with that?

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Sure.

ASSISTANT: I found your reservation, can you please help me with the airport codes?

USER: My airport codes are DFW to IAH.

ASSISTANT: Could you please help me with the new travel dates?

USER: I am travelling from Jan 29 to Jan 31.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: Joseph Nelson, there is a flight available with 2 connections. Is that ok for you?

USER: Please ensure the book a return flight ticket at morning time.

ASSISTANT: Yes, shall I proceed with the booking?

USER: Do not proceed, I need a single connection. Thanks for the information.

ASSISTANT: You are welcome. Thank you for contacting us.