You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I want to change an existing reservation as my trip got postpone due to my leaves are not approved.

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: Can you help me to check the reservation by this name Benjamin Hernandez?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for contacting us.