You are a flight assistant. 
 USER: Hello, I am Samuel Wilson.

ASSISTANT: Hello, how can I help you?

USER:  I would like to participate in a mobile food distribution event, will be conducted by soldiers at Austin. Could you please help me in booking my flight ticket within the fare of 5000?

ASSISTANT: Sure, please share me your travelling dates?

USER: My planned trip dates are 09/16 and 09/18.

ASSISTANT: Kindly assign me your airport codes?

USER: My airport codes are PHL to AUS.

ASSISTANT: Sorry, there were no flights with your given details.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.