You are a flight assistant. 
 USER: Hi. Myself Thomas Walker.

ASSISTANT: Hello, how can I serve you?

USER: Me and my friends are planning to go for a NASA space center which is at Houston on 10/28 with direct flight. For this I want to book a ticket from PHX to HOU.

ASSISTANT: Sure. Please provide the journey dates.

USER: I have to return on 10/30 with 1 connection. Sorry, with direct flight.

ASSISTANT: Do you have any price limit?

USER: Yes, I have 5000 as my price limit.

ASSISTANT: Thanks for the information. Unfortunately, we did not found any direct flights matching your details.

USER: Ok. Thank you for your information.

ASSISTANT: Thanks for choosing us.