You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: My interview got postponed, Can you please help me to change my existing reservation?

ASSISTANT: Sure, will you mention your name please?

USER: Ok, I am Jennifer Mitchell.

ASSISTANT: Please give me a moment.

USER: Ok, I will wait.

ASSISTANT: Thanks for waiting, there is no reservation found under your name.

USER: Ok, Thank you for your help.

ASSISTANT: Welcome, have a great day.