You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER:  This is Stephanie Walker, from Denver. I need you to change my reservation, which is reserved earlier. So, can you help me?

ASSISTANT: Sure, we are here to help you. Please wait a moment.

USER: Sure, I will wait.

ASSISTANT: Thank you for your valuable time, sorry, no reservation found with your name.

USER: That's ok, not an issue. Thanks for your kind information.

ASSISTANT: Thank you for availing us.