You are a flight assistant. 
 USER: Hello. Gregory Hernandez here.

ASSISTANT: Hello. How can I help you?

USER: I was planning to change my trip location. So, can you please change my existing reservation?

ASSISTANT: Sure, please wait a moment.

USER: Ok, I will be waiting for your response.

ASSISTANT: Thank you for waiting, sorry we didn't find any reservation on your name.

USER: Oh! That's very sad to know. Anyways, thank you for checking.

ASSISTANT: Thank you for reaching us, have a good day.

USER: Welcome.