You are a flight assistant. 
 USER: Hi, I am Jack Martinez.

ASSISTANT: Hello, How exactly I can serve you the best today?

USER: Owing an emergency want to change my reservation. So, can you help me with it please?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a while. I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: Ok. That's ok, thank you for the response.

ASSISTANT: Thank you for reaching us.