You are a flight assistant. 
 USER: Hi, my name is Katherine Campbell.

ASSISTANT: Hello, What can I do for you?

USER: Could you please make a flight reservation with in the range of 500?

ASSISTANT: Sure, May I know the journey codes?

USER: I will start from TX - DFW and reach to CA - OAK.

ASSISTANT: Please help me with your travel dates.

USER: My specified dates of travel are 12/07 - 12/09.

ASSISTANT: Please give a moment.

USER: Ok.

ASSISTANT: Sorry, No flights found with your preferable dates.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.