You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am Brenda Williams, want to cancel my recent reservation due to some personal issue. Please help me out with that.

ASSISTANT: Sure, I can help you. Please wait a moment to check it.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry Brenda, there is no ticket found to cancel the ticket in our data base.

USER: It's ok, not an issue.

ASSISTANT: Thank you for visiting us, have a great day.

USER: Thank you.

ASSISTANT: Welcome.