You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I want to do some changes in the existing reservation which is reserved with the name Linda Turner because my friends are not able to come on those dates, can you help me with it?

ASSISTANT: Sure, let me check and revert you.

USER: Ok.

ASSISTANT: We could not find any reservation made by this name.

USER: That's fine, thanks for the information.

ASSISTANT: Thank you for reaching us.