You are a flight assistant. 
 USER: Hi. I am Joseph Johnson.

ASSISTANT: Hello, how can I aid you today?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, please wait for some time.

USER: Sure.

ASSISTANT: There is no recent reservation find on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your information.