You are a flight assistant. 
 USER: Hello, I am Melissa Edwards.

ASSISTANT: Hello, how can I give assistance to you?

USER: I want to change my existing reservation, due to some personal work.

ASSISTANT: Sure, we are here to change your reservation. Please be on hold.

USER: Sure.

ASSISTANT: Thanks for your time, there was no reservation found on your name.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for reaching our service.