You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Ok, sure can you please let me know your name?

USER: I am Susan Martinez.

ASSISTANT: Ok, I have found your reservation. Can you please let me know your new travelling dates?

USER: My travelling dates are from 05/23 to 05/25.

ASSISTANT: Please share your travelling codes?

USER: My airport codes are from OAK to DFW.

ASSISTANT: Sorry, no flight found on your new preferable dates.

USER: Anyway, thanks for the information.

ASSISTANT: Most welcome.