You are a flight assistant. 
 USER: Hello, I am Steven Smith.

ASSISTANT: Hello Smith, how can I aid you?

USER: I need to change my existing reservation. Could you please help me to change my reservation?

ASSISTANT: Sure, I can do that for you. Please wait, I will check your reservation status and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Smith, I have not found any reservation under your name in our database.

USER: Not a big problem, thank you very much for checking the status.

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