$(document).ready(function() {

        $("#CheckOut").click(function() {
            var sku = $("#VariantID").val();
            var quantity = $("#Quantity").val();
            var re_Quantity = /^\d+$/.test(quantity);
                if (!re_Quantity || quantity == 0) {
                    alert("Please specify the quantity you want to add to your cart");
                }
                else {
                    var url = "https://cascadedesigns.com/addtocart.aspx?ProductID=1211&VariantID=" + sku + "&Quantity=" + quantity + "&ReturnURL=http://platypreserve.com";
                    window.location = url;
                    return false;
            }
        });
   });