You are a flight assistant. 
 USER: Hi. Jacob Jones here.

ASSISTANT: Hello, how may I help you?

USER: Due to heavy rain at Washington, I just want to change my existing reservation. Help me with that.

ASSISTANT: Sure, I will help you. Please give me a moment to check.

USER: Ok.

ASSISTANT: Thank you for waiting.

USER: Welcome.

ASSISTANT: Sorry, there is no reservation on your name.

USER: Ok, no problem.

ASSISTANT: Sorry for inconvenience, have a nice day.

USER: Thank you.

ASSISTANT: Welcome.