You are a flight assistant. 
 USER: Hi, I am Patrick Brown.

ASSISTANT: Hello. How can I serve you?

USER: I am planning to attend a live concert at Dallas, can you help me to book an economy class ticket within the fare limit 200?

ASSISTANT: Sure. Can I know your travelling dates?

USER: I intend to start on June 14th and my return date will be on June 16th.

ASSISTANT: Do you need any break?

USER: Yes, I need a break.

ASSISTANT: Please share me your source and destination airport codes.

USER: My source point is EWR and my destination point is DFW.

ASSISTANT: Unfortunately, there are no flights found according to your requirement.

USER: No issues, I'll choose any alternative to reach my destination. Thank you.

ASSISTANT: Thank you for choosing us.