You are a flight assistant. 
 USER: Hello. Myself Dennis Hall.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation, can you help me?

ASSISTANT: Sure Dennis Hall, I am here to help you out. Please allow me a moment to check the reservation on your name.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry Dennis Hall, there is no reservation on your name in our database.

USER: That's ok, thank you for the information.

ASSISTANT: Thank you for reaching us.