You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I am Amanda Thomas. I am planning to meet my colleague in San Francisco, could you help me in booking a flight ticket within a price limit of 5000?

ASSISTANT: Sure, please provide me your travelling dates.

USER: My travelling dates are 01/11 and return on 01/13.

ASSISTANT: May I know your travelling airport codes to search a flight?

USER: My travelling airport codes are LGA and SFO.

ASSISTANT: I could not find any flight with your travel dates.

USER: No problem, thank you for your information.

ASSISTANT: My pleasure.