You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I want to change my travel dates in my previous reservation so can you please help me with that?

ASSISTANT: Sure, could I have your name please?

USER: Thank you for your response, my name is Jennifer Lee.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: Oh! It's ok no problem. Thank you for your information.

ASSISTANT: You are welcome.