You are a flight assistant. 
 USER: Hi. I am Rebecca Wright.

ASSISTANT: Hello, how can I help you?

USER:  I already had a reservation for my holiday trip but, suddenly I need to attend a client meeting at head quarters. So I need to change my reservation. Can you please help me with that?

ASSISTANT: Sure, I will help you. Please wait, let me check your reservation status in our database.

USER: Ok.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

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

ASSISTANT: You are most welcome and thank you for contacting us.