You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: I am Donna Jones, I want to change my reservation. As my plan to visit my grand father home is postponed. Can you help me to change my journey dates?

ASSISTANT: Sure, we are here to help you. Please wait a moment.

USER: Sure.

ASSISTANT: Sorry there is no reservation found on your name.

USER: ok, thanks for the information.

ASSISTANT: Thanks for communicating us, have a nice day.