You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I serve you today?

USER: I am Michelle Evans. I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, I'll help you in changing an existing reservation. Please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for waiting, unfortunately there is no reservation found by this name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for choosing us.