With Sheets("Numero_de_Serie")
If TextBox1.Value = "" Then
MsgBox "Entrez un code svp", , "Erreur"
ElseIf TextBox1.Value = WorksheetFunction.VLookup(TextBox1.Value, Sheets("Base_Article").Range("B3:B32"), 1, False) Then
TextBox2.Value = WorksheetFunction.VLookup(TextBox1.Value, Sheets("Base_Article").Range("B3: D32"), 2, False)
ElseIf TextBox1.Value <> WorksheetFunction.VLookup(TextBox1.Value, Sheets("Base_Article").Range("B3:B32"), 1, False) Then
MsgBox "Code non reconnu", , "Erreur"
End If