You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am a pharmaceutical student, I have zoology exam in IAH on 01/12. So I need to go for IAH in flight, please help me in booking my flight ticket?

ASSISTANT: May I know your preferable dates please?

USER: My journey starting date is 01/11 and my return date is 01/13.

ASSISTANT: May I know your source code please?

USER: I want to start my journey from my home place DFW?

ASSISTANT: May I know your name please?

USER: Ok, myself Patricia Johnson.

ASSISTANT: I am sorry no flights available on your rough.

USER: Ok, fine not an issue. Thank you for your help.

ASSISTANT: Thank you for choosing us.