Variable nicht definiert

Private Sub ListBox1_Click()
If ListBox1.Value  "" And Calendar1.Value  "" Then
CB1.Enabled = True
End If
End Sub

Option Explicit
Private Sub Calendar1_Click()
If Calendar1.Value  "" And ListBox1.Value  "" Then
CB1.Enabled = True
End If
End Sub
Private Sub CB1_Click()
'daten einsammeln
MyName = ListBox1.Value
Letzter = Calendar1.Value
Me.Hide
End Sub
Private Sub CB2_Click()
'benutzerabbruch
Me.Hide
End Sub
Private Sub LoadlistBox(lBox As ListBox, Ary)
With lBox
.Clear
.ColumnCount = 1
.List = Ary
End With
End Sub
Private Sub ListBox1_Click()
If ListBox1.Value  "" And Calendar1.Value  "" Then
CB1.Enabled = True
End If
End Sub