Validation impossible si TextBox pas remplie

Bonjour,

J'ai un Userform dans lequel je souhaiterais intégrer la condition suivante: si la TextBox1 n'est pas remplie on ne peut pas valider la saisie. Je suis très débutante en VBA, je ne sais pas donc pas trop quoi écrire et où l'insérer.

Dim f


Private Sub ComboBox6_Change()

End Sub

Private Sub Label1_Click()

End Sub

Private Sub Label2_Click()

End Sub

Private Sub Label3_Click()

End Sub

Private Sub Label4_Click()

End Sub

Private Sub Label5_Click()

End Sub

Private Sub Label6_Click()

End Sub

Private Sub Label7_Click()

End Sub

Private Sub TextBox1_Change()

End Sub

Private Sub TextBox2_Change()

End Sub

Private Sub UserForm_Initialize()
  Set f = Sheets("BDD")
  Set mondico = CreateObject("Scripting.Dictionary")
  For Each C In f.Range("A3:A" & f.[A65000].End(xlUp).Row)
    mondico(C.Value) = ""
  Next C
  temp = mondico.keys
  Call Tri(temp, LBound(temp), UBound(temp))
  Me.ComboBox1.List = temp
End Sub
Private Sub ComboBox1_click()
  Me.ComboBox2.Clear
  Me.ComboBox3.Clear
  Me.ComboBox4.Clear
  Me.ComboBox5.Clear
  Set mondico = CreateObject("Scripting.Dictionary")
  For Each C In f.Range("A3:A" & f.[A65000].End(xlUp).Row)
    If C = Me.ComboBox1 Then mondico(C.Offset(, 1).Value) = ""
  Next C
  temp = mondico.keys
  Call Tri(temp, LBound(temp), UBound(temp))
  Me.ComboBox2.List = temp
End Sub
Private Sub ComboBox2_click()
  Me.ComboBox3.Clear
  Me.ComboBox4.Clear
  Me.ComboBox5.Clear
  Set mondico = CreateObject("Scripting.Dictionary")
  For Each C In f.Range("A3:A" & f.[A65000].End(xlUp).Row)
    If C = Me.ComboBox1 And C.Offset(, 1) = Me.ComboBox2 Then mondico(C.Offset(, 2).Value) = ""
  Next C
  temp = mondico.keys
  Call Tri(temp, LBound(temp), UBound(temp))
  Me.ComboBox3.List = temp
End Sub
Private Sub ComboBox3_click()
  Me.ComboBox4.Clear
  Me.ComboBox5.Clear
  Set mondico = CreateObject("Scripting.Dictionary")
  For Each C In f.Range("A3:A" & f.[A65000].End(xlUp).Row)
    If C = Me.ComboBox1 And C.Offset(, 1) = Me.ComboBox2 And C.Offset(, 2).Value = Me.ComboBox3 Then mondico(C.Offset(, 3).Value) = ""
  Next C
  temp = mondico.keys
  Call Tri(temp, LBound(temp), UBound(temp))
  Me.ComboBox4.List = temp
End Sub
Private Sub ComboBox4_click()
  Me.ComboBox5.Clear
  Set mondico = CreateObject("Scripting.Dictionary")
  For Each C In f.Range("A3:A" & f.[A65000].End(xlUp).Row)
    If C = Me.ComboBox1 And C.Offset(, 1) = Me.ComboBox2 And C.Offset(, 2).Value = Me.ComboBox3 And C.Offset(, 3).Value = Me.ComboBox4 Then mondico(C.Offset(, 4).Value) = ""
  Next C
  temp = mondico.keys
  Call Tri(temp, LBound(temp), UBound(temp))
  Me.ComboBox5.List = temp
End Sub


Sub Tri(a, gauc, droi) ' Quick sort
  ref = a((gauc + droi) \ 2)
  g = gauc: d = droi
  Do
    Do While a(g) < ref: g = g + 1: Loop
    Do While ref < a(d): d = d - 1: Loop
      If g <= d Then
        temp = a(g): a(g) = a(d): a(d) = temp
        g = g + 1: d = d - 1
      End If
    Loop While g <= d
    If g < droi Then Call Tri(a, g, droi)
    If gauc < d Then Call Tri(a, gauc, d)
End Sub

Private Sub CommandButton1_Click()
Dim DerLig As Integer
 
With Worksheets("Saisie")
    DerLig = .Range("B" & Rows.Count).End(xlUp).Row + 1
    .Range("C" & DerLig).Value = ComboBox1.Value
    .Range("D" & DerLig).Value = ComboBox2.Value
    .Range("E" & DerLig).Value = ComboBox3.Value
    .Range("F" & DerLig).Value = ComboBox4.Value
    .Range("G" & DerLig).Value = ComboBox5.Value
    .Range("B" & DerLig).Value = ComboBox6.Value
    .Range("H" & DerLig).Value = TextBox1.Value
    .Range("K" & DerLig).Value = TextBox2.Value
End With
 
Unload UserForm1
 
End Sub

Merci pour votre aide.