Laufzeifehler

Private Sub ListBox1_Click()
Dim wks1 As Worksheet
Dim s1 As Integer
Dim a1 As Integer
s1 = 1
For Each wks1 In Worksheets
If s1 = 3 Or s1 = 4 Or s1 = 5 Or s1 = 7 Or s1 = 8 Or s1 = 9 Or s1 = 10 Then
ListBox1.AddItem wks1.name, a1
a1 = a1 + 1
End If
s1 = s1 + 1
If a1 > 7 Then
ListBox1.Clear
End If
Next wks1
End Sub

Private Sub ListBox2_Click()
Dim wks2 As Worksheet
Dim s2 As Integer
Dim a2 As Integer
s2 = 1
For Each wks2 In Worksheets
If s2 = 23 Or s2 = 16 Or s2 = 13 Or s2 = 20 Or s2 = 22 Or s2 = 19 Or s2 = 18 Or s2 = 106 Or s2 = 107 Or s2 = 21 Or s2 = 108 Or s2 = 14 Or s2 = 12 Or s2 = 24 Or s2 = 17 Or s2 = 15 Then
ListBox2.AddItem wks2.name, a2
a2 = a2 + 1
End If
s2 = s2 + 1
If a2 > 7 Then
ListBox2.Clear
End If
Next wks2
End Sub