Measure popped corn into a large bowl. In a small saucepan, combine sugar, syrup, water, and salt. Cover tightly and bring to a rolling boil. Remove lid and add thermometer. Cook to 270 degrees; remove from heat and stir in vanilla. Pour cooked syrup over the popped corn, stirring to coat corn. Cool completely, then run through a food chopper. Melt chocolate coating in top of double boiler. Stir ground popcorn into chocolate, using as much popcorn as the chocolate will hold. Pack into chocolate lined molds or roll out between waxed paper and cut into shapes with cookie cutters or knives. Makes about 50 pieces. Recipe from:Ideals Candy Cookbook by Mildred Brand Copyright-MCMLXXIX By Mildred Brand, Milwaukee, Wis. 53201