You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I address you?

USER: i would like to cancel my recent reservation as my plan to meet my grand parents got postpone due to my health issues. Can you please help me with this?

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Can I know your name?

USER: I am David Evans.

ASSISTANT: We didn't found any reservation by this name.

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

ASSISTANT: Thank you for consulting us.