You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: I am Christopher Johnson, my holiday trip got postponed to next month. Can you help me to change my reservation?

ASSISTANT: Sure, please wait for a moment meanwhile I will check your details and revert you.

USER: Please check my details in your records.

ASSISTANT: Sorry to say, I did not found any details regarding your reservation in my database.

USER: That's fine, I think it was already changed by my friend.

ASSISTANT: Thank you for contacting us. Have a pleasant day!.

USER: Thank you.