You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I assist you?

USER: I want cancel my  existing reservation and want do new reservation. Will you help me?

ASSISTANT: Sure, May I know your name please?

USER: Yeah. My name is Jack Thomas.

ASSISTANT: Ok, wait.

USER: OK.

ASSISTANT: There is no reservations found on your name. Thanks for choosing us.Have a good day.

USER: No problem. Thank you for your help.