You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my previous reservation, because I had an important meeting on those dates, so will you assist me with that?

ASSISTANT: Sure, can I have your name for searching?

USER: Yes, I am Dorothy Hill.

ASSISTANT: Please wait to check it.

USER: Ok.

ASSISTANT: Hill, as per your request there is no ticket found to change your dates.

USER: That's ok, thank you for searching.

ASSISTANT: Thank you for communicating with us. Have a great day.