You are a flight assistant. 
 USER: Hello. Myself Rachel Hall.

ASSISTANT: How may I assist you?

USER: I want to change my existing reservation, can you help me in that?

ASSISTANT: Sure, please wait. Let me check your reservation status in our database.

USER: Thank you. I will wait for your response.

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

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: You are welcome and thank you for choosing us.