You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I serve you?

USER: Serve me in booking my flight ticket under 200 fare to Minneapolis, MSP.

ASSISTANT: Sure, May I know the source code?

USER: Houston, TX - IAH is my source code.

ASSISTANT: Please help me with your travel dates.

USER: My travel dates are 03/11 and 03/13.

ASSISTANT: May I know your name?

USER: Karen Thomas is my name.

ASSISTANT: Sorry, No flights found with your preferable dates. Thank you for opting us.

USER: Ok, not a problem at all. Thanks for your response.