You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Donald Rodriguez.

ASSISTANT: How may I help you today?

USER: I am planning to attend music concert at IAD, can you please help me with booking a flight ticket from IAH?

ASSISTANT: Ok, I will help you. Can I have your travelling dates?

USER: My trip dates are May 20 to May 22.

ASSISTANT: Do have any other specifications?

USER: I need a direct flight.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: No issue, thank you.

ASSISTANT: Thank you for reaching us.