You are a flight assistant. 
 USER: Hello, I am Mary Harris.

ASSISTANT: Hello, how can I help you today?

USER: I need a reservation to meet my project manager. Can you please book a ticket with a price limit of 5000?

ASSISTANT: Sure, Can you please let me know your travelling dates?

USER: My travelling dates are from 04/22 to 04/24.

ASSISTANT: Please let me know your origin airport code?

USER: My boarding airport is Boston, BOS and landing airport is San Francisco, SFO.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no flights found with your requirement.

USER: That's not a problem. Alright, thank you for your fast response.

ASSISTANT: Thanks for reaching us.