You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation due to my health issues, can you please help me with this?

ASSISTANT: Sure. Please let me know your name?

USER: I am Timothy Anderson.

ASSISTANT: Let me check status with your recent reservation.

USER: Ok.

ASSISTANT: Sorry, there is no reservation by your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you. Have a nice day ahead!.