You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I provide assistance to you?

USER: I am looking for a direct flight for my journey, can you please help me to search a flight from Washington to Los Angeles?

ASSISTANT: Sure, we are here to make your journey comfort.

USER: Thank you for your response.

ASSISTANT: Can you please provide me your airport abbreviates?

USER: The airport codes are IAD to LAX.

ASSISTANT: Ok, when did you scheduled to travel & return?

USER: The departure and arrival dates are Dec 25 and Dec 27.

ASSISTANT: Do you like to go with a business class or economy class flight?

USER: I don't have any preference in class.

ASSISTANT: Ok, please wait for a moment.

USER: Ok, take your time and make sure that the price limit is 5000 or less.

ASSISTANT: Sure, for that I need to know your name. Can you please provide me?

USER: My name is Dorothy Thomas.

ASSISTANT: We are sorry to inform you that, there are no flights available on your requested dates because as it a Festival season.

USER: It's ok, not a problem with that. Thank you for your help.

ASSISTANT: Thank you.