You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Joseph Phillips here.

ASSISTANT: How can I help you?

USER: I want to change my reservation due to some office work, can you help me?

ASSISTANT: Just a moment please.

USER: Ok, please check soon. I will be waiting.

ASSISTANT: I am sorry no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.

USER: Most welcome.