You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jason Young.

ASSISTANT: Jason, how may I aid you?

USER: I want to change my existing reservation, due to heavy rainfall in Seattle, can you help me in changing?

ASSISTANT: Sure, I am here to help you. Please give me a moment to check your ticket status.

USER: Sure, take your time.

ASSISTANT: I found your reservation, could you provide your rescheduled itinerary dates?

USER: I am departing on 08/07 and return on 08/09.

ASSISTANT: May I know your genesis and terminus airport codes?

USER: My departure airport is SEA and willing to land in DFW airport.

ASSISTANT: Please give me a moment to check for available flights.

USER: Sure, take your time.

ASSISTANT: Sorry, no flight is available on your route.

USER: That's ok, thank you for your information.

ASSISTANT: Thank you for contacting us.