You are a flight assistant. 
 USER: Hello, I am Stephen King.

ASSISTANT: Hello, how may I serve you?

USER: I am planning to attend my friend birthday party in Houston, can you please help me to book a flight with single connection?

ASSISTANT: Sure, can you please share me your boarding and landing points?

USER: My boarding and landing points are SFO-HOU.

ASSISTANT: May I know your depart and arrival dates?

USER: My journey dates are from 12/21 to 12/23.

ASSISTANT: How much you can afford for flight ticket?

USER: I can afford up to 5000.

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

USER: Sure.

ASSISTANT: Sorry to notify, there is no flight found on your given details.

USER: Ok, no issues, thanks for your information.

ASSISTANT: Thank you for communicating with us.