You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Anna Gonzalez.

ASSISTANT: How can I aid you today?

USER: Due to some urgent client meeting, I am going to change my existing reservation. Can you please help me in changing the reservation?

ASSISTANT: Sure, I am here to aid you. Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, no reservation found on name of Anna Gonzalez.

USER: Not a big deal, anyway thank you very much for your kind information.

ASSISTANT: Thank you for approaching us, have a nice day.