You are a flight assistant. 
 USER: Hello, I am Frank Clark.

ASSISTANT: Hello. How can I be at your service?

USER: Can you please book a direct flight to San Francisco, SFO as I am planning to attend for my grand parents 60th wedding anniversary?

ASSISTANT: Sure, I am happy to help you.

USER: Thank you.

ASSISTANT: May I know, where will you take off?

USER: I would like to board from Houston, IAH.

ASSISTANT: Please, share your start and return dates that you have planned to travel.

USER: My depart is on 03/07 and return is on 03/09.

ASSISTANT: How much you can afford for this journey?

USER: I can afford up to 200.

ASSISTANT: Thank you for sharing the details.

USER: Ok.

ASSISTANT: Sorry to inform you that, there is no direct flight available that matches your requirements.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.