Another Mitchell restaurant, this time a longtime chain fast food restaurant, has closed its doors.  Burger King on North Main Street was not open for business on Tuesday.  Customers there were met with locked doors and a sign which read TO OUR VALUED CUSTOMERS: WE REGRET TO INFORM YOU THAT THIS RESTAURANT IS NO LONGER OPEN FOR BUSINESS.  THANK YOU FOR YOUR SUPPORT.  Earlier this year, Burger King announced plans to close up to 400 restaurants by the end of the year.  The company that operated Mitchell’s Burger King, Meridian Restaurants Unlimited, filed for bankruptcy this year.