You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Thomas Lopez.

ASSISTANT: Lopez, how may I help you?

USER: I am planning to change my previous reservation, can you help me?

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

USER: Sure, take your time.

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

USER: That's fine. Anyway, thank you for your help.

ASSISTANT: Thank you for reaching us.