You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I make a reservation to Washington DC to meet my family but at my office I have to attend a meeting on travelling dates. So I postponed my journey with new dates. Can you change my reservation with new dates?

ASSISTANT: Sure, could you please share your name to proceed further?

USER: My name is Thomas Carter.

ASSISTANT: Ok, please wait for a while, let me check your reservation and revert to you.

USER: Sure.

ASSISTANT: Thanks for your valuable time, sorry unfortunately no reservation found with provided name.

USER: Ok, thanks for the information.

ASSISTANT: Thanks for connecting with us, have a great day ahead.