You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Donna Jones.

ASSISTANT: How can I assist you?

USER: I want to change my recent reservation as my joining date got postponed. Can you help me in changing?

ASSISTANT: Ok, please wait for a while. Sorry, no reservation found on our name to change.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Ok, fine thank you for reaching us.