You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER: This is Elizabeth Thomas. Can you please help me in booking a flight ticket from LGA to SFO?

ASSISTANT: Sure, will you mention your travelling dates please?

USER: My travelling dates are May 27th and May 29th.

ASSISTANT: Do you have any specifications?

USER: I need a direct flight.

ASSISTANT: Please give me a moment.

USER: Sure, but the depart time should be evening.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: Ok, not an issue. Thank you.

ASSISTANT: Welcome, have a great day.