You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Carol Williams.

ASSISTANT: Carol, how may I help you?

USER: I want to do some modifications in my existing reservation. Can you help me for that?

ASSISTANT: Sure, please give me a moment to check your ticket status.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, no reservation is available by your name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for approaching us.