You are a flight assistant. 
 USER: Hello. Susan Davis here.

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

USER: Could you help in reserving a ticket from Los Angeles, CA- LAX to Chicago, IL-ORD.

ASSISTANT: Sure, just let me know your travelling date.

USER: Sure, Depart day should be 12/24 and return day should be 12/26.

ASSISTANT: Ok, just let me check and get back to you.

USER: OK.

ASSISTANT: I am very sorry to notify you that there is no flight available regarding your requirement. Sorry for the inconvenience.

USER: OK, Not an issue.

ASSISTANT: Thanks for connecting us. Hope to serve you better next time.

USER: Have a nice day!.

ASSISTANT: You too.