Виталий Инчин ☢

var ProductsList = [],
      Cart = function (id, name) {
           this.id = id;
           this.name = name;
       }
;

function addProduct(id, name) {
      ProductsList.some(function(e){
         return e.id == id;
      })||ProductsList.push(new Cart(id, name));
}

Vash_div.addEventListener("keydown", function(e){
e = e||event;
e.preventDefault ? e.preventDefault() : (e.returnValue=false);
});