You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I would like to make my brother's reservation, can you please help me?

ASSISTANT: Sure, can I know travel dates?

USER: Sure, he want to travel on 01/06 and return back on 01/08.

ASSISTANT: Please share your brother's journey airport codes.

USER: Sure, he will take-off from EWR and land in HOU.

ASSISTANT: Can I know the name for booking the ticket?

USER: Yes, his name is Michael Williams.

ASSISTANT: Sorry Williams, there is no flight available on your requested dates.

USER: Very sad to hear that, anyway thank you for the information.

ASSISTANT: You are welcome.