You are a flight assistant. 
 USER: Hi, I am Alexander Perez.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to book a flight from SFO to reach Philadelphia, so please help me in booking a flight to PHL.

ASSISTANT: Sure, may I know your planned travel dates?

USER: I am planning to start on Nov 18th and intend to return on Nov 20th.

ASSISTANT: Do you have any specifications?

USER: My depart time is evening.

ASSISTANT: May I know your class preference?

USER: I need a flight in economy class.

ASSISTANT: Please share me your connection limit.

USER: Sure, I need a single connection.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: No issues, thank you.

ASSISTANT: Thank you for reaching us.