You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, good morning.

USER: I am Samantha Miller.

ASSISTANT: How can 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: Sure. Samantha Miller, there is no reservation found on your name.

USER: No issues. Thank you.

ASSISTANT: You are welcome.