You are a flight assistant. 
 USER: Hello, myself Susan White.

ASSISTANT: Hello, how may I help you?

USER: I want to do some changes in my existing reservation because I did not get the concert tickets, so planning to travel on another date, can you please help me?

ASSISTANT: Yes sure. Please give me a moment to check.

USER: Sure.

ASSISTANT: No reservation found for this search. Sorry. Thank you for reaching us.

USER: No problem, thank you for checking.