added more helper methods.

Views/Shared/_Layout.cshtml

@@ -65,6 +65,11 @@
             input = input.replace(decimalSeparator, ".");
             return parseFloat(input);
         }
+        function globalFloatToString(input) {
+            var decimalSeparator = "@numberFormat.NumberDecimalSeparator";
+            input = input.replace(".", decimalSeparator);
+            return input;
+        }
     </script>
     @await RenderSectionAsync("Scripts", required: false)
 </head>

wwwroot/js/gasrecord.js

@@ -99,12 +99,12 @@ function getAndValidateGasRecordValues() {
     }
     if (gasCostType != undefined && gasCostType == 'unit') {
         var convertedGasCost = globalParseFloat(gasCost) * globalParseFloat(gasGallons);
-        gasCost = convertedGasCost.toFixed(2).toString();
-        if (isNaN(gasCost))
+        if (isNaN(convertedGasCost))
         {
             hasError = true;
             $("#gasRecordCost").addClass("is-invalid");
         } else {
+            gasCost = globalFloatToString(convertedGasCost.toFixed(2).toString());
             $("#gasRecordCost").removeClass("is-invalid");
         }
     }