You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Owing to an emergency, I want to cancel my reservation. Can you help me out?

ASSISTANT: On which name can I cancel the reservation?

USER: I have reserved the ticket on the name of Helen Thompson.

ASSISTANT: I am sorry no reservation found on your name. Thank you for choosing us.

USER: That's ok, thank you.