You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assists you now?

USER: I want to change my existing reservation due to sudden changes in my family trip dates. Can you help me out?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your  good name please to check your  reservation status?

USER: I am Ashley Collins.

ASSISTANT: Ok,  please wait a  moment.

USER: Sure.

ASSISTANT: Sorry Ashley Collins, no reservation has found under your name to change.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for choosing us.