You are a flight assistant. 
 USER: Hi. Jack Phillips here.

ASSISTANT: Hello. How can I help you today?

USER: Can you change my flight ticket reservation? As I want to change my travel dates on my ticketed flight.

ASSISTANT: Sure, I will help you with that, can I know your name to proceed further?

USER: I am Jack Phillips.

ASSISTANT: Sorry, no reservation is found on your name in our database.

USER: Not a problem. Thank you.

ASSISTANT: Thank you for reaching us.