diff --git a/scripts/ad_users_sa_window.ps1 b/scripts/ad_users_sa_window.ps1
index 0515040..7a17381 100644
--- a/scripts/ad_users_sa_window.ps1
+++ b/scripts/ad_users_sa_window.ps1
@@ -37,39 +37,42 @@ $dataGridView.AlternatingRowsDefaultCellStyle.BackColor = [System.Drawing.Color]
 $dataGridView.add_CellEndEdit({
     param ($sender, $e)
     $row = $dataGridView.Rows[$e.RowIndex]
-
-    # Felder schreibgeschützt machen, wenn Typ SA ist
-    if ($row.Cells["Type"].Value -eq 'SA') {
-        $row.Cells["FirstName"].ReadOnly = $true
-        $row.Cells["LastName"].ReadOnly = $true
-    } else {
-        $row.Cells["FirstName"].ReadOnly = $false
-        $row.Cells["LastName"].ReadOnly = $false
-    }
     
-    # Name und SAMAccountName generieren
+    # Name generieren
     if ($row.Cells["FirstName"].Value -ne $null -and $row.Cells["LastName"].Value -ne $null -and $row.Cells["FirstName"].Value -ne "" -and $row.Cells["LastName"].Value -ne "") {
         $row.Cells["Name"].Value = $row.Cells["FirstName"].Value + " " + $row.Cells["LastName"].Value
-        $samAccountName = $row.Cells["FirstName"].Value.Substring(0, 1).ToLower() + $row.Cells["LastName"].Value.ToLower()
+
+        # SAMAccountName generieren
+        $firstName = $row.Cells["FirstName"].Value.ToLower() -replace "ä", "ae" -replace "ö", "oe" -replace "ü", "ue"
+        $lastName = $row.Cells["LastName"].Value.ToLower() -replace "ä", "ae" -replace "ö", "oe" -replace "ü", "ue"
+        $samAccountName = $firstName.Substring(0, 1) + $lastName
         $row.Cells["SAMAccountName"].Value = $samAccountName
-        
+
         # UPN generieren
         $dcParts = $row.Cells["DC"].Value -replace "DC=", "" -split ","
         $upnDomain = ($dcParts -join ".").ToLower()
         $row.Cells["UPN"].Value = "$samAccountName@$upnDomain"
     }
 
-    # OU und DC von der darüber liegenden Master-Zeile übernehmen
-    $aboveMasterRow = $null
-    for ($i = ($e.RowIndex - 1); $i -ge 0; $i--) {
-        if ($dataGridView.Rows[$i].Cells["Type"].Value -eq 'Master') {
-            $aboveMasterRow = $dataGridView.Rows[$i]
-            break
+    # OU und DC vom darüberliegenden Master übernehmen
+    if ($row.Cells["Type"].Value -ne 'Master') {
+        for ($i = ($e.RowIndex - 1); $i -ge 0; $i--) {
+            if ($dataGridView.Rows[$i].Cells["Type"].Value -eq 'Master') {
+                $masterRow = $dataGridView.Rows[$i]
+                $row.Cells["OU"].Value = $masterRow.Cells["OU"].Value
+                $row.Cells["DC"].Value = $masterRow.Cells["DC"].Value
+                break
+            }
         }
     }
-    if ($aboveMasterRow -ne $null) {
-        $row.Cells["OU"].Value = $aboveMasterRow.Cells["OU"].Value
-        $row.Cells["DC"].Value = $aboveMasterRow.Cells["DC"].Value
+
+    # FirstName und LastName-Feld schreibgeschützt machen, wenn Typ SA ist
+    if ($row.Cells["Type"].Value -eq 'SA') {
+        $row.Cells["FirstName"].ReadOnly = $true
+        $row.Cells["LastName"].ReadOnly = $true
+    } else {
+        $row.Cells["FirstName"].ReadOnly = $false
+        $row.Cells["LastName"].ReadOnly = $false
     }
 })
 
@@ -117,11 +120,9 @@ foreach ($row in $data) {
                 break
             }
         }
-        
-        $ou = if ($row.OU) { $row.OU } else { $aboveMasterRow.OU }
-        $dc = if ($row.DC) { $row.DC } else { $aboveMasterRow.DC }
-        $row.OU = $ou
-        $row.DC = $dc
+
+        $row.OU = if ($row.OU) { $row.OU } else { $aboveMasterRow.OU }
+        $row.DC = if ($row.DC) { $row.DC } else { $aboveMasterRow.DC }
     }
 }
 
@@ -138,7 +139,9 @@ foreach ($row in $data) {
             $name = if ($row.Name) { $row.Name } else { $row.FirstName + " " + $row.LastName }
 
             # SAMAccountName und UPN generieren
-            $samAccountName = $row.FirstName.Substring(0, 1).ToLower() + $row.LastName.ToLower()
+            $firstName = $row.FirstName.ToLower() -replace "ä", "ae" -replace "ö", "oe" -replace "ü", "ue"
+            $lastName = $row.LastName.ToLower() -replace "ä", "ae" -replace "ö", "oe" -replace "ü", "ue"
+            $samAccountName = $firstName.Substring(0, 1) + $lastName
             $dcParts = $row.DC -replace "DC=", "" -split ","
             $upnDomain = ($dcParts -join ".").ToLower()
             $upn = "$samAccountName@$upnDomain"