You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Jack Scott here.

ASSISTANT: I am here to help you.

USER: Can you change my flight ticket reservation?

ASSISTANT: Yes, can you wait while I check the records of the reservation please?

USER: Sure.

ASSISTANT: Sorry, there is no reservation found.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for choosing our agency.