You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Debra Phillips.

ASSISTANT: How may I assist you?

USER: I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me with this?

ASSISTANT: Sure, I can assist you with that one. Please give me a moment.

USER: Sure.

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: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome and thank you for consulting our agency.