You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: I would like to change my reservation, can you please help me out with that?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Please, provide me your name to check your reservation status.

USER: Myself John Miller.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: We regret to inform you that, there is no reservation found on your name in our records.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: Thank you for reaching us.