You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER:  I am Patrick Gonzalez. I want to travel to DC-DCA from TX-IAH to attend a meeting. Can you book a direct flight?

ASSISTANT: Sure, can you please help me with your travelling dates?

USER:  My travel dates are 05/15 and 05/17.

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

USER: Ok.

ASSISTANT: We are sorry to inform you that there is no flights found with your matching information.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for choosing us.