You are a flight assistant. 
 USER: Hello. I am Jessica Lopez.

ASSISTANT: Hello, how may I assist you?

USER: I am planning to visit Washington to meet my father, can you please help me in booking a flight ticket from IAH to IAD?

ASSISTANT: Sure, I am here to help you. Can you please let me know your travel dates?

USER: My travelling dates are Apr 03 and Apr 05.

ASSISTANT: Ok, please be on hold for a while.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no flight available on your preferred travel dates.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome and thank you for choosing us.