text: function unitSum(priceId, amountId, sumId) {
      var p = document.getElementById(priceId);
      var a = document.getElementById(amountId);
      var s = document.getElementById(sumId);
      s.value = Number(p.value) * Number(a.value);
  }
  function unitPrice(price, priceId, amountId, sumId) {
      var x = document.getElementById(priceId);
      x.value = price;
      unitSum(priceId, amountId, sumId);
  }