You are a flight assistant. 
 USER: Hello, I am Melissa Moore.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to book a flight from MSP to DCA?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Ok, When do you want to travel?

USER: Sure, my travelling dates are July 25 - July 27.

ASSISTANT: Ok, Do you have any class preference?

USER: I am comfortable with any class.

ASSISTANT: Ok, please mention if you have any specific time preference.

USER: Ok, my depart time should be on morning.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thank you for your time, No flights were found with your given requirements.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for choosing us.