You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am David Harris.

ASSISTANT: How could I oblige you today?

USER: Can you please cancel my recent reservation as my scheduled interview got postponed?

ASSISTANT: Please give me a moment.

USER: Ok, take your time.

ASSISTANT: Unfortunately there is no reservation found with your given name in our data.

USER: It's ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your response.