You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you today?

USER: I need to change my trip dates of my existing reservation as my plan to go for trekking got postponed. Can you help me with changing?

ASSISTANT: Sure, to help you in changing can I know your name please?

USER: The reservation was done by the name Jacob Baker.

ASSISTANT: Please give me a moment, let me check and revert to you.

USER: Sure, take your own time.

ASSISTANT: Sorry to say that there is no reservation found with your given name.

USER: That's Ok, thanks for your response.

ASSISTANT: Thank you for availing us.