You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Melissa Hall here.

ASSISTANT: How can I assist you at this moment?

USER: I am having sudden meeting in my office, can you please help me changing my reservation?

ASSISTANT: Sure Hall, I will help you with that.

USER: Thanks.

ASSISTANT: Please wait a moment to check your reservation status.

USER: Sure, take your time.

ASSISTANT: Sorry Melissa Hall, no reservation has found under your name to change.

USER: Ok, no problem. Thank you for your help.

ASSISTANT: Thank you for choosing us, have a good day.