You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: Earlier I have made a reservation, but your agent misplaced my travel dates , so I need to modify my reservation. Can you help me to change my existing reservation?

ASSISTANT: Sure, on what name your reservation was made earlier?

USER: I have made my earlier reservation on name David Thompson.

ASSISTANT: Ok, let me check the status and revert to you.

USER: Sure.

ASSISTANT: There is no active reservation found b the name you mentioned.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.