You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Joseph Clark. Due to my health problem I want to change my reservation, can you please help me in that?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Please give me a minute, I will get back to you with current status.

USER: Ok, I will wait for your information.

ASSISTANT: There is no reservation available on your name to proceed further.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for reaching us.