You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER:  I am Daniel Green want to change my reservation due to prepone of my meeting. Can you help me in changing?

ASSISTANT: Sure, we are glad to help you. By what name you have done the reservation earlier?

USER: I have done reservation on name Daniel Green.

ASSISTANT: Please wait, I will check the reservation list and get back to you.

USER:  Ok.

ASSISTANT: Thanks for waiting, no reservation was found by your name in the database.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.