Change period to comma in amount input textbox

MainWindow.xaml.cs

@@ -59,5 +59,10 @@ namespace CryptoCalc
             t.Comment = "Test";
             return t;
         }
+
+        private void inputAmount_LostFocus(object sender, RoutedEventArgs e)
+        {
+            inputAmount.Text = inputAmount.Text.Replace(".", ",");
+        }
     }
 }