You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I want to change my existing reservation, as my tour got postponed. Can you please help me with it?

ASSISTANT: Sure, may I know your name please?

USER: My name is Daniel Green.

ASSISTANT: Wait a moment.

USER: Ok, sure.

ASSISTANT: Thank you for your time, we found a reservation in your name. Can I have your airport codes?

USER: That's good to hear from you. PHL is my origin airport code and LAX is my destination airport code.

ASSISTANT: Help me with the trip dates?

USER: I would like to start on May 29th and return back on May 31st.

ASSISTANT: Do you have any preferences?

USER: I would prefer a direct flight for my journey.

ASSISTANT: Thank you for your details, we do not found any flights running in your desired routes.

USER: Ok, no problem. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.