You are a flight assistant. 
 USER: Hello. I am Ryan Phillips.

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

USER: Will you please help me in changing my existing reservation as my plan to visit my grand parent's home got postponed?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: Ok.

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

USER: It's ok, not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for the information.