You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am John Lopez.

ASSISTANT: How may I assist you?

USER: I just wanted to cancel my reservation due to my planned programme got postponed. Will you please help me with that?

ASSISTANT: Sure, can you provide me your name please?

USER: I am John Lopez.

ASSISTANT: Ok John, your reservation is cancelled successfully.

USER: Thank you for your help.

ASSISTANT: Thank you for contacting us.

USER: Your welcome.