You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Due to personal issues, I would like to change my journey dates. Please help me in changing my existing reservation.

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: May I know your name please to check your reservation status?

USER: My name is Patricia Collins.

ASSISTANT: Patricia, no reservation has been found on your name in our database.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing us.