You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I serve you today?

USER: Can you help me in changing my existing reservation due to my misplace of dates in previous reservation?

ASSISTANT: Sure, could you please share your name to proceed further?

USER: I am Barbara Clark.

ASSISTANT: Ok, please wait for a while, let me check your reservation with us and get back to you.

USER: Sure.

ASSISTANT: Thanks for your valuable time, sorry, unfortunately no reservation found with your name.

USER: Ok, no problem. Thank you for assisting me.

ASSISTANT: Thanks for reaching us, have a great day ahead.