You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Ronald Parker here.

ASSISTANT: Parker, how can I help you?

USER: It's my birthday party, I want to give my birthday party to my friends in HOU. Can you please check once is there any flight available on 08/29?

ASSISTANT: Sure, let me check, please wait for a moment.

USER: Ok.

ASSISTANT: Please provide your source airport code and return date.

USER: My current location is IAD and I have to return on 08/31.

ASSISTANT: Sorry, no flights found.

USER: It's ok. Thank you for your valuable time.

ASSISTANT: Thank you for contacting us.