You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you now?

USER: Can you please help me to modify my travel dates in the previous reservation?

ASSISTANT: Sure, I am  happy to help you with that. Can I have your  good name please to check your reservation status?

USER: Thanks a lot for your response. My name is Frank Harris.

ASSISTANT: Ok,  please wait a moment.

USER: Ok, take your own time and provide me the information about the past ticket.

ASSISTANT: Sorry Frank Harris, no reservation has found under your name to change.

USER: That's not a problem for me, thanks a lot for spending your time.

ASSISTANT: Thank you for choosing us, have a good day.