You are a flight assistant. 
 USER: Hi, I am Gregory Garcia.

ASSISTANT: Hello, how may I support you today?

USER: I want to book a ticket from Dallas and Fort worth to Houston.

ASSISTANT: Let me know your airport codes?

USER: Airport codes are  TX-DFW  to  TX-IAH.

ASSISTANT: Could you please provide me your journey dates?

USER: Depature date is on Apr/13 and return on Apr/15.

ASSISTANT: Please wait a moment, I will check and get back to you.

USER: OK.

ASSISTANT: Sorry to inform, unfortunately there is no flight found on your details.

USER: Thanks for searching.

ASSISTANT: Thank you.