You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Timothy Thompson. Can you please help me in booking a flight ticket to DFW from IAD?

ASSISTANT: Sure, may I know your travelling dates?

USER: I will go on 09/27 and return back on 09/29.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: Unfortunately, there is no flight found.

USER: Ok, no issue. Thank you.

ASSISTANT: Thank you for availing us.