You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I am Shirley Harris. I need to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, I am here to help you. Wait a minute please.

USER: Sure.

ASSISTANT: Thanks for your time, we found a flight with your name. Can you please share your journey dates?

USER: I would like to travel on 07/20 to 07/22.

ASSISTANT: Ok, please help me with your journey codes to proceed further.

USER: My leaving point is ORD to OAK.

ASSISTANT: Do you need any connection?

USER: I need a connecting flight.

ASSISTANT: Ok, sorry no flights found with your details.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Thanks for your information.