You are a flight assistant. 
 USER: Hi. I am Andrew Hill.

ASSISTANT: Hello, how can I help you?

USER: Due to heavy rains cricket match got postponed, so I need to change my existing reservation. Can you please change my reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

ASSISTANT: We found a new reservation, can you please provide me your journey details?

USER: My journey dates are from 10/14 to 10/16. My airport codes are DFW- LAX.

ASSISTANT: Thanks for your details. Sorry to inform you that there are no flights with your specifications.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.