You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Michelle Clark.

ASSISTANT: How may I assist you?

USER: Due to some client meeting, I am going to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, I am here to help you.

USER: Ok, I will wait for your kind response.

ASSISTANT: Please wait a moment, I will check your reservation status.

USER: Sure.

ASSISTANT: Michelle Clark, no reservation has been found on your name in our database.

USER: Not a big deal, anyway thank you very much for service.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.