You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how could I assist you today?

USER: As I have an important work, for that I am requesting you to change my existing reservation with the name of Donna Hall. Please help me in doing this.

ASSISTANT: Sure, I am here to help you. Please wait for some time. I will check with your existing reservation status.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no recent reservation found on your name in our records.

USER: No problem, I will check for another option. Thank you for your information.

ASSISTANT: Thank you for approaching us.