You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I render you today?

USER: Mary Martin here, due to sudden work I need to change my reservation. Could you please help me with it?

ASSISTANT:  Sure, I will help you with that. Please wait a while.

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: Not an issue. Thank you.

ASSISTANT: Thank you for reaching us.