diff --git a/WGneu/App.xaml.cs b/WGneu/App.xaml.cs
index 5afc810..81a3a22 100644
--- a/WGneu/App.xaml.cs
+++ b/WGneu/App.xaml.cs
@@ -21,22 +21,22 @@ namespace WGneu {
             MainDispatcher = Dispatcher;
         }
 
-        protected override void OnStartup(StartupEventArgs e) {
+        protected override void OnStartup(StartupEventArgs evt) {
             Utils.RunBackground("HTML Initialization", () => Documents.Html.Init(PrintingReadyChanged));
             Utils.RunBackground("PDF Initialization", () => Documents.Pdf.Init(PrintingReadyChanged));
-            base.OnStartup(e);
+            base.OnStartup(evt);
         }
 
-        protected override void OnExit(ExitEventArgs e) {
+        protected override void OnExit(ExitEventArgs evt) {
             Utils.RunBackground("PDF Close", () => Documents.Pdf.Close());
-            base.OnExit(e);
+            base.OnExit(evt);
         }
 
         private void PrintingReadyChanged() {
             Dispatcher.BeginInvoke(OnPrintingReadyChanged, new EventArgs());
         }
 
-        protected void OnPrintingReadyChanged(EventArgs e) {
+        protected void OnPrintingReadyChanged(EventArgs evt) {
             foreach (Window w in Windows) {
                 foreach (var b in Utils.FindVisualChilds<Button>(w).Where(b => "Print".Equals(b.Tag))) {
                     b.IsEnabled = IsPrintingReady;
diff --git a/WGneu/Windows/ContractListWindow.xaml.cs b/WGneu/Windows/ContractListWindow.xaml.cs
index ab0557b..b0a266b 100644
--- a/WGneu/Windows/ContractListWindow.xaml.cs
+++ b/WGneu/Windows/ContractListWindow.xaml.cs
@@ -1,17 +1,8 @@
 using Microsoft.EntityFrameworkCore;
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Shapes;
 using WGneu.Helpers;
 using WGneu.Models;
 
@@ -32,7 +23,7 @@ namespace WGneu.Windows {
                 ContractList.SelectedIndex = 0;
         }
 
-        private void ContractList_SelectionChanged(object sender, SelectionChangedEventArgs e) {
+        private void ContractList_SelectionChanged(object sender, SelectionChangedEventArgs evt) {
             RefreshContractList();
         }
     }
diff --git a/WGneu/Windows/DeliveryReceptionWindow.xaml.cs b/WGneu/Windows/DeliveryReceptionWindow.xaml.cs
index cc30dfe..152ea85 100644
--- a/WGneu/Windows/DeliveryReceptionWindow.xaml.cs
+++ b/WGneu/Windows/DeliveryReceptionWindow.xaml.cs
@@ -1,16 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Shapes;
+using System.Windows;
 
 namespace WGneu.Windows {
     public partial class DeliveryReceptionWindow : Window {
diff --git a/WGneu/Windows/DocumentViewerWindow.xaml.cs b/WGneu/Windows/DocumentViewerWindow.xaml.cs
index 13d3ae4..efdaa09 100644
--- a/WGneu/Windows/DocumentViewerWindow.xaml.cs
+++ b/WGneu/Windows/DocumentViewerWindow.xaml.cs
@@ -1,16 +1,5 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Shapes;
 using WGneu.Helpers;
 
 namespace WGneu.Windows {
@@ -28,7 +17,7 @@ namespace WGneu.Windows {
             PdfFile = file;
         }
 
-        public void OnClosed(object sender, EventArgs e) {
+        public void OnClosed(object sender, EventArgs evt) {
             PdfFile?.Dispose();
             PdfFile = null;
         }
diff --git a/WGneu/Windows/MainWindow.xaml.cs b/WGneu/Windows/MainWindow.xaml.cs
index 68103fb..37769da 100644
--- a/WGneu/Windows/MainWindow.xaml.cs
+++ b/WGneu/Windows/MainWindow.xaml.cs
@@ -7,45 +7,35 @@ using System.Runtime.Intrinsics.X86;
 using System.Text;
 using System.Threading.Tasks;
 using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Navigation;
-using System.Windows.Shapes;
 using WGneu.Documents;
 using WGneu.Helpers;
-using WGneu.Models;
-
 
 namespace WGneu.Windows {
     public partial class MainWindow : Window {
-        private readonly WgContext _context = new WgContext();
+        private readonly WgContext Context = new();
 
         public MainWindow() {
             InitializeComponent();
         }
 
-        private void Window_Loaded(object sender, RoutedEventArgs e) {
-            _context.Countries.Load();
+        private void Window_Loaded(object sender, RoutedEventArgs evt) {
+            Context.Countries.Load();
             Button4.IsEnabled = App.IsPrintingReady;
         }
 
-        protected override void OnClosing(CancelEventArgs e) {
-            _context.Dispose();
-            base.OnClosing(e);
+        protected override void OnClosing(CancelEventArgs evt) {
+            Context.Dispose();
+            base.OnClosing(evt);
         }
 
-        private void Button2_Click(object sender, EventArgs e) {
+        private void Button2_Click(object sender, RoutedEventArgs evt) {
             var w = new MemberListWindow();
             w.Show();
         }
 
-        private void Button4_Click(object sender, EventArgs e) {
+        private void Button4_Click(object sender, RoutedEventArgs evt) {
             Utils.RunBackground("PDF Generation", async () => {
-                using var letter = new BusinessLetter("Test Dokument", _context.Members.First());
+                using var letter = new BusinessLetter("Test Dokument", Context.Members.First());
                 await letter.Generate();
                 letter.Show();
             });
diff --git a/WGneu/Windows/MemberListWindow.xaml.cs b/WGneu/Windows/MemberListWindow.xaml.cs
index 4b75116..54da458 100644
--- a/WGneu/Windows/MemberListWindow.xaml.cs
+++ b/WGneu/Windows/MemberListWindow.xaml.cs
@@ -1,21 +1,11 @@
-using Microsoft.Data.Sqlite;
-using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore;
 using System;
 using System.Collections.Generic;
 using System.ComponentModel;
-using System.Diagnostics.Metrics;
 using System.Linq;
-using System.Net;
-using System.Text;
-using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
 using System.Windows.Input;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Shapes;
 using WGneu.Helpers;
 using WGneu.Models;
 
@@ -44,15 +34,15 @@ namespace WGneu.Windows {
                 Valid[tb] = true;
         }
 
-        private void Window_Loaded(object sender, RoutedEventArgs e) {
+        private void Window_Loaded(object sender, RoutedEventArgs evt) {
             ActiveMemberInput.IsChecked = true;
             BranchInput.ItemsSource = Context.Branches.OrderBy(b => b.Name).ToList();
             DefaultKgInput.ItemsSource = Context.WbKgs.Select(k => k.Kg).OrderBy(k => k.Name).ToList();
         }
 
-        protected override void OnClosing(CancelEventArgs e) {
+        protected override void OnClosing(CancelEventArgs evt) {
             Context.Dispose();
-            base.OnClosing(e);
+            base.OnClosing(evt);
         }
 
         private int CountMatchesInMember(Member m) {
@@ -122,15 +112,15 @@ namespace WGneu.Windows {
             MgNrInput.Text = NextMgNr().ToString();
         }
 
-        private void MemberList_SelectionChanged(object sender, SelectionChangedEventArgs e) {
+        private void MemberList_SelectionChanged(object sender, SelectionChangedEventArgs evt) {
             RefreshInputs();
         }
 
-        private void ActiveMemberInput_Changed(object sender, RoutedEventArgs e) {
+        private void ActiveMemberInput_Changed(object sender, RoutedEventArgs evt) {
             RefreshMemberList();
         }
 
-        private void NewMemberButton_Click(object sender, RoutedEventArgs e) {
+        private void NewMemberButton_Click(object sender, RoutedEventArgs evt) {
             IsCreating = true;
             MemberList.IsEnabled = false;
             InitInputs();
@@ -140,7 +130,7 @@ namespace WGneu.Windows {
             LockSearchInputs();
         }
 
-        private void EditMemberButton_Click(object sender, RoutedEventArgs e) {
+        private void EditMemberButton_Click(object sender, RoutedEventArgs evt) {
             if (MemberList.SelectedItem == null)
                 return;
 
@@ -153,7 +143,7 @@ namespace WGneu.Windows {
             LockSearchInputs();
         }
 
-        private void DeleteMemberButton_Click(object sender, RoutedEventArgs e) {
+        private void DeleteMemberButton_Click(object sender, RoutedEventArgs evt) {
             Member m = (Member)MemberList.SelectedItem;
             if (m == null) return;
 
@@ -167,7 +157,7 @@ namespace WGneu.Windows {
             }
         }
 
-        private void SaveButton_Click(object sender, RoutedEventArgs e) {
+        private void SaveButton_Click(object sender, RoutedEventArgs evt) {
             Member? m = new();
             if (IsEditing)
                 m = (Member)MemberList.SelectedItem;
@@ -237,7 +227,7 @@ namespace WGneu.Windows {
             RefreshMemberList();
         }
 
-        private void ResetButton_Click(object sender, RoutedEventArgs e) {
+        private void ResetButton_Click(object sender, RoutedEventArgs evt) {
             if (IsEditing) {
                 RefreshInputs();
             } else if (IsCreating) {
@@ -246,7 +236,7 @@ namespace WGneu.Windows {
             UpdateButtons();
         }
 
-        private void CancelButton_Click(object sender, RoutedEventArgs e) {
+        private void CancelButton_Click(object sender, RoutedEventArgs evt) {
             IsEditing = false;
             IsCreating = false;
             MemberList.IsEnabled = true;
@@ -257,21 +247,21 @@ namespace WGneu.Windows {
             UnlockSearchInputs();
         }
 
-        private void ContractButton_Click(object sender, RoutedEventArgs e) {
+        private void ContractButton_Click(object sender, RoutedEventArgs evt) {
             var w = new ContractListWindow((Member)MemberList.SelectedItem);
             w.Show();
         }
 
-        private void SearchInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void SearchInput_TextChanged(object sender, RoutedEventArgs evt) {
             TextFilter = SearchInput.Text.ToLower().Split(" ").ToList().FindAll(s => s != "");
             RefreshMemberList();
         }
 
-        private void Menu_Member_SendEmail_Click(object sender, EventArgs e) {
+        private void Menu_Member_SendEmail_Click(object sender, EventArgs evt) {
             Utils.MailTo(((Member)MemberList.SelectedItem).Email);
         }
 
-        private void FocusSearchInput(object sender, RoutedEventArgs e) {
+        private void FocusSearchInput(object sender, RoutedEventArgs evt) {
             if (!IsEditing && !IsCreating) {
                 SearchInput.Focus();
                 SearchInput.SelectAll();
@@ -497,7 +487,7 @@ namespace WGneu.Windows {
                 MessageBox.Show(res.ErrorContent.ToString(), msg ?? res.ErrorContent.ToString(), MessageBoxButton.OK, MessageBoxImage.Warning);
         }
 
-        private void CheckBox_Changed(object sender, RoutedEventArgs e) {
+        private void CheckBox_Changed(object sender, RoutedEventArgs evt) {
             var input = (CheckBox)sender;
             if (InputHasChanged(input)) {
                 Utils.SetInputChanged(input);
@@ -507,7 +497,7 @@ namespace WGneu.Windows {
             UpdateButtons();
         }
 
-        private void RadioButton_Changed(object sender, RoutedEventArgs e) {
+        private void RadioButton_Changed(object sender, RoutedEventArgs evt) {
             var input = (RadioButton)sender;
             if (InputHasChanged(input)) {
                 Utils.SetInputChanged(input);
@@ -517,7 +507,7 @@ namespace WGneu.Windows {
             UpdateButtons();
         }
 
-        private void TextBox_TextChanged(object sender, RoutedEventArgs e) {
+        private void TextBox_TextChanged(object sender, RoutedEventArgs evt) {
             var input = (TextBox)sender;
             if (InputHasChanged(input)) {
                 Utils.SetInputChanged(input);
@@ -527,7 +517,7 @@ namespace WGneu.Windows {
             UpdateButtons();
         }
 
-        private void ComboBox_SelectionChanged(object sender, RoutedEventArgs e) {
+        private void ComboBox_SelectionChanged(object sender, RoutedEventArgs evt) {
             var input = (ComboBox)sender;
             if (InputHasChanged(input)) {
                 // TODO not working
@@ -538,62 +528,62 @@ namespace WGneu.Windows {
             UpdateButtons();
         }
 
-        private void PlzInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void PlzInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, false, Validator.CheckPlz);
             UpdatePlz((TextBox)sender, OrtInput);
         }
 
-        private void PlzInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void PlzInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckPlz, null);
             UpdatePlz((TextBox)sender, OrtInput);
         }
 
-        private void PhoneNrInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void PhoneNrInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckPhoneNumber);
         }
 
-        private void PhoneNrInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void PhoneNrInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckPhoneNumber, null);
         }
 
-        private void EmailInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void EmailInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckEmailAddress);
         }
 
-        private void EmailInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void EmailInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckEmailAddress, null);
         }
 
-        private void IbanInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void IbanInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckIban);
         }
 
-        private void IbanInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void IbanInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckIban, null);
         }
 
-        private void BicInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void BicInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckBic);
         }
 
-        private void BicInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void BicInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckBic, null);
         }
 
-        private void LfbisNrInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void LfbisNrInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckLfbisNr);
         }
 
-        private void LfbisNrInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void LfbisNrInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckLfbisNr, "Betriebsnummer ungültig");
         }
 
-        private void BillingPlzInput_TextChanged(object sender, RoutedEventArgs e) {
+        private void BillingPlzInput_TextChanged(object sender, RoutedEventArgs evt) {
             InputTextChanged((TextBox)sender, true, Validator.CheckPlz);
             UpdatePlz((TextBox)sender, BillingOrtInput);
         }
 
-        private void BillingPlzInput_LostFocus(object sender, RoutedEventArgs e) {
+        private void BillingPlzInput_LostFocus(object sender, RoutedEventArgs evt) {
             InputLostFocus((TextBox)sender, true, Validator.CheckPlz, null);
             UpdatePlz((TextBox)sender, BillingOrtInput);
         }