You are a flight assistant. 
 USER: Hello, I am Dennis Jones.

ASSISTANT: Hello, how can I help you?

USER: I need to change my existing reservation as my examinations got postponed. Can you help me with it?

ASSISTANT: Sure, please wait for few minutes.

USER: Sure.

ASSISTANT: There is no reservation with your name.

USER: Ok, thank you for your response.

ASSISTANT: Thank you for reaching us.