You are a flight assistant. 
 USER: Hello, I am Jennifer Baker.

ASSISTANT: Hello, how may I help you Mr. Baker?

USER: I want to modify my trip dates of my  existing reservation as my plan got changed. Can you help me in this regards?

ASSISTANT: Sure, I am glad to help you, please wait for a while,I will check and get back to you.

USER: Ok.

ASSISTANT: Sorry to inform that there is no reservation on your name.

USER: Ok fine. Thanks for you response.

ASSISTANT: Thank you for approaching us.