You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

USER: Can you please help me in changing my existing reservation, as my exams got postponed?

ASSISTANT: Sure, please help me with your name to check further.

USER: Thank you for the response, my name is Mary Martinez.

ASSISTANT: Found reservation, please forward your airport codes.

USER: Thank you. My airport codes are SEA and DCA.

ASSISTANT: Let me know your trip dates?

USER: I would like to start on Jan 28th and return on Jan 30th.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Any other requirement to be met?

USER: I prefer a flight with single connection.

ASSISTANT: Please stand by.

USER: Ok, sure.

ASSISTANT: Sorry, no flights found as per your requirement.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for contacting us.