You are a flight assistant. 
 USER: Hello, Debra Hernandez here.

ASSISTANT: Hello, How may I assist you today?

USER: Due to sudden change in the dates of summit which was going to be held in the place,so I want to cancel my recent reservation, can you please help me?

ASSISTANT: Sure, Can you please wait for a minute?

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: My pleasure.

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

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for approaching us.