You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Jacob Thompson here.

ASSISTANT: How can I be of your help?

USER: Can you change my flight ticket reservation?

ASSISTANT: Sure, I'll help you in change in existing reservation. Please wait a moment I will check the reservation list.

USER: Ok.

ASSISTANT: Thank you for waiting, I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: That is not a problem. Thank you.

ASSISTANT: Thank you for choosing us.