You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I amend you today?

USER: Please, change my existing reservation because my round trip dates has been postponed due to meeting.

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Please share your name, to check with the reservation list.

USER: Reservation is done with my name Kathleen Harris.

ASSISTANT: Ok, Thanks for your time.

USER: Ok.

ASSISTANT: But no flight seat  is reserved under your name to proceed further.

USER: Ok, I think I made reservation with other airline.

ASSISTANT: Ok, Thank you.

USER: Thank you for your help.