You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mary More.

ASSISTANT: How may I assist you?

USER: I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Ok, under which name you have made your reservation?

USER: Mary Moore is my cousin name you can check this .

ASSISTANT: Give me a moment please.

USER: OK.

ASSISTANT: There is no reservation by the name of Mary Moore, sorry.

USER: No issue.

ASSISTANT: Thank you for consulting us.

USER: Thank you for your quick response.

ASSISTANT: Have a nice day.