You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I need to change my existing reservation because of some health issue. Can you please help me in doing that?

ASSISTANT: Sure, may I know your name  to check your reservation status?

USER: I am Eric Johnson.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: We have a found a reservation on your name. Please, share me your airport codes.

USER: I will take off from PHL to land at ORD.

ASSISTANT: May I know your travel dates?

USER: Ok, my updated journey dates are Jan 13 and Jan 15.

ASSISTANT: Do you have any connection limit?

USER: I need a flight having single connection.

ASSISTANT: May I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: Do you have any more specifications?

USER: Yes, my depart time should be evening.

ASSISTANT: Let me know your name to proceed.

USER: I mentioned already.

ASSISTANT: Sorry, we have not found any flights running on your desired dates.

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

ASSISTANT: Thank you for reaching us.