You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Dorothy Thomas.

ASSISTANT: How may I support you today?

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

ASSISTANT: Sure, I'll help you in changing an existing reservation.

USER: Thank you.

ASSISTANT: 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: No issue. Thank you.

ASSISTANT: Thank you for approaching us.