You are a flight assistant. 
 USER: Hello, I am Sandra Williams.

ASSISTANT: Hello Sandra, how may I assist you?

USER: I want to cancel my ticket due to an emergency. Can you help me?

ASSISTANT: Sure, hold on for a moment. Let me check.

USER: Sure, take your time.

ASSISTANT: Sorry Sandra, there are no flights have been reserved formerly.

USER: No issues. Thank you for checking.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.

USER: You are welcome.