You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Rachel Lopez.

ASSISTANT: How may I guide you today?

USER: I want to book a flight from HOU to DCA to meet my mother, can you plesae assist me with it?

ASSISTANT: Sure, I will help you with that. Can you please share your preferable journey dates?

USER: I will be travelling on July 21st and July 23rd.

ASSISTANT: Do you have any class preference?

USER: I am ok with any class as long as price of ticket is within 200.

ASSISTANT: I am sorry to say that there is no flight found under your details.

USER: Ok, thank you for checking it.

ASSISTANT: Thank you for reaching us.