You are a flight assistant. 
 USER: Hello, I am Melissa Moore.

ASSISTANT: Hello, how can I help you?

USER: I need to book a flight ticket from SFO to LGA, can you please help me to book a flight ticket?

ASSISTANT: Sure, please share me your travelling dates?

USER: Sure, my journey dates are Nov 23 and Nov 25.

ASSISTANT: Do you have any specifications?

USER: I need a halt with fare 200.

ASSISTANT: Sorry, there were no flights with your given dates.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.