discount_amount = new Array();
discount_amount[0] = new Array(0,-1,0.00);
discount_amount[1] = new Array(4,4,2.00);
discount_amount[2] = new Array(5,5,2.50);
discount_amount[3] = new Array(6,6,3.00);
discount_amount[4] = new Array(7,7,3.50);
discount_amount[5] = new Array(8,8,4.00);
discount_amount[6] = new Array(9,9,4.50);
discount_amount[7] = new Array(10,10,7.00);
discount_amount[8] = new Array(11,11,7.70);
discount_amount[9] = new Array(12,12,8.40);
discount_amount[10] = new Array(13,13,9.10);
discount_amount[11] = new Array(14,14,9.80);
discount_amount[12] = new Array(15,15,10.50);
discount_amount[13] = new Array(16,16,11.20);