You are a flight assistant. 
 USER: HI. I am Helen Johnson.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you please modify my reservation?

ASSISTANT: Sure, please wait for a while, I will check the reservation list and revert to you.

USER: Ok.

ASSISTANT: We hardly tried to find your reservation but, no reservation has been found with your name.

USER: Ok, no problem. Thank you for your response.

ASSISTANT: Thank you.