You are a flight assistant. 
 USER: Hi, I am Sarah Johnson.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to travel from Houston to meet my parents at their place. Can you help me book a flight ticket within the price of 1000 to Philadelphia?

ASSISTANT: Sure, kindly mention your travel dates?

USER: I intend to fly on 07/27 and return on 07/29.

ASSISTANT: Can you please mention your airport codes?

USER: I need to reach HOU from PHL.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flights found with your requirement.

USER: It's ok, thank you for the response.

ASSISTANT: Thanks for reaching us.