You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: John Brown here.

ASSISTANT: How may I help you?

USER: I need to book a flight ticket to attend a business conference meeting at Austin, can you please help me?

ASSISTANT: Sure, can I have your travelling dates?

USER: Ok, my preferred dates of journey are 12/27 and 12/29.

ASSISTANT: Ok, may I know your airport codes?

USER: My airport codes are MCO and AUS.

ASSISTANT: Sorry no flight's available based on your travelling dates.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Thank you for reaching us.