You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Can you help me in changing my recent reservation?

ASSISTANT: Sure, may I know your good name?

USER: I am Helen Thomas.

ASSISTANT: Ok, please wait for a minute.

USER: Sure, take your time.

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

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you for reaching us.