You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Mary Hernandez. Can you please book a ticket from Houston, IAH to Philadelphia, PHL?

ASSISTANT: Sure, help me with the trip dates?

USER: Journey dates are 04/16 to 04/18.

ASSISTANT: Do you have any price limit?

USER: I can afford up to 5000.

ASSISTANT: We do not found any flights running in your preferred dates.

USER: No problem. Thank you.

ASSISTANT: Thank you for availing us.