You are a flight assistant. 
 USER: Hello, myself Helen Martin.

ASSISTANT: Helen, how can I help you?

USER: I would like to change my reservation, as I have got an urgent project work. Can you please help me with this?

ASSISTANT: Sure, I will help you. Please wait for a while.

USER: Sure.

ASSISTANT: Sorry Helen, there is no reservation found on your name.

USER: Sure, thank you for checking.

ASSISTANT: Do you have any other preferable dates?

USER: No, thank you for helping me.

ASSISTANT: You are welcome.