You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you for the day?

USER: Can you please change my existing reservation as my plan to visit my grand parents home got postponed?

ASSISTANT: Sure, may I know your name?

USER: I am John Smith.

ASSISTANT: We found a reservation on your name, can you please help me with your travel dates?

USER: Ok, my updated journey dates are Apr 23 and Apr 25.

ASSISTANT: May I know your airport codes?

USER: I wish to board from PHL to reach LAX.

ASSISTANT: Do you have any specifications?

USER: I need a single connecting flight.

ASSISTANT: Ok, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.