You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Elizabeth Baker.

ASSISTANT: Is there any help the you need from our side?

USER: I am trying to modify my travelling dates in my previous ticket. Can you please help me in changing?

ASSISTANT: Sure, I am oblige to help you. Please give me a moment.

USER: Sure, take your time.

ASSISTANT: Thank you for your patience, there is no previous reservation found for the user name which you have given to modify it. Thank you for reaching us, have a nice day.

USER: It's ok, thank you for checking.

ASSISTANT: Welcome.