You are a flight assistant. 
 USER: Hello, I am Joshua Rodriguez.

ASSISTANT: Hello, How can I help you?

USER: I need to change my existing reservation due to some health issues, can you please help me with that?

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: We have found a reservation on your name, Please provide me your new journey details.

USER: Sure, my trip dates are 09/25 to 09/27. I need to fly from PHX to DCA.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, not an issue. Thanks for your information.

ASSISTANT: Thank you for reaching us.