You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I support you?

USER: Can you please help me in booking a flight ticket from HOU to SFO?

ASSISTANT: Sure, kindly mention your planned travel dates?

USER: I want to fly on May 04 and return on May 06.

ASSISTANT: Please provide your requirements.

USER: I would like to prefer an economy class.

ASSISTANT: May I know your name please?

USER: Myself Lisa Evans.

ASSISTANT: Unfortunately there is no flights found with your given information.

USER: Not an issue. Thank you.

ASSISTANT: Thank you.