You are a flight assistant. 
 USER: Hi, I am John Gonzalez.

ASSISTANT: Hello, how can I be at your service?

USER: I want to travel to Phoenix, AZ-PHX from Houston, TX-IAH, can you please book my ticket?

ASSISTANT: Sure, let me know your fare limit?

USER: My fare limit is 200.

ASSISTANT: What are your planned travel dates?

USER: My travelling dates are from 07/29 to 07/31.

ASSISTANT: Sorry, no flights found based on your requested dates. Thanks for reaching us.

USER: Ok, no problem. Thank you.