You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Can you help me to change my existing reservation as my holiday trips got postponed?

ASSISTANT: Let me know your name.

USER: I am Kathleen Edwards.

ASSISTANT: Sorry, no reservation found by your name.

USER: Ok, not a problem.

ASSISTANT: Thank you.

USER: Thank you.