You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I'm Helen Wilson.

ASSISTANT: How may I assist you today?

USER: My examination scheduled dates has been postponed.So, I would like to change my recent reservation which is under my name. Can you please help me with that?

ASSISTANT: Sure, please wait for a minute.

USER: Sure, take your time.

ASSISTANT: I found a reservation with your name, can you provide me your new travel details?

USER: Sure, my travel dates are 03/08 and the 03/10.

ASSISTANT: Airport codes?

USER: My airport codes are from DFW to IAH.

ASSISTANT: Sorry, I cannot find a flight with your new details.

USER: That's really sad. Anyways, thank you for checking.

ASSISTANT: Thanks for contacting us, have a great day.