You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you?

USER: I want to modify my trip dates as my plan to go for trekking got postponed. Can you help me?

ASSISTANT: Sure, I can help you.

USER: Thank you.

ASSISTANT: Provide me your name so that I can check your reservation status.

USER: I am Elizabeth White.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT:  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Ok fine, thanks for your response.

ASSISTANT: Thank you for reaching us.