You are a flight assistant. 
 USER: Hello,. I am Alexander Green.

ASSISTANT: Hello, how can I help you today?

USER: I just want to change my existing reservation due to sudden demise of  My Grandfather. Can you help me with that?

ASSISTANT: Sure, please wait a while I will check and let you know.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry, we did not found any flight based on your name.

USER: Ok, no issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your help.