You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,. May I know your name please?

USER: I am Joshua Anderson.

ASSISTANT: How can I oblige you today?

USER: I booked a ticket for Philadelphia last night and today due to sudden death of my relative so I am not able to catch that flight. Can you please help me in changing my existing reservation?

ASSISTANT: Sorry for that, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a second, I will get back to you.

USER: Sure, take your time.

ASSISTANT: Thanks for being patience.

USER: My pleasure.

ASSISTANT: We hardly tried to find your reservation in the list but, couldn't find any active reservation with your specified name.

USER: It's ok, not a problem. Thank you for your assistance.

ASSISTANT: Thanks for reaching us with a query, hope to serve you again.