You are a flight assistant. 
 USER: Hello. I am Jessica Nelson.

ASSISTANT: Hello, how may I assist you?

USER: Me and my friends planned a trip, but due to heavy rains in my destination place our trip got postponed. So can you please help me to change an existing reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: We found a reservation, can you please share me your travel dates?

USER: My travelling dates are from 06/26 to 06/28.

ASSISTANT: Could you please share me your airport codes?

USER: My airport codes are from DTW to OAK.

ASSISTANT: There is no flight on your details.

USER: That's not a problem. Thanks for your information.

ASSISTANT: Thank you.