You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Margaret Allen, would it be possible to change my reservation to new travelling dates?

ASSISTANT: Sure, please give me a moment to check your ticket status.

USER: Sure, take your own time.

ASSISTANT: Sorry, no reservation is available by your name.

USER: It's ok, no issues. Thanks for checking.

ASSISTANT: Thank you for choosing us.