You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Can you please change my reservation as my plan to go for trekking got postponed. Can you help me?

ASSISTANT: Yes, can you tell me your name?

USER: Dorothy Miller here.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for contacting us.