Private Sub userform_initialize()
Label_error_ref.Visible = False
ComboBox_client.MatchEntry = fmMatchEntryNone
ListClients = Application.Transpose(Sheets(2).Range("B1:B" & Sheets(2).[B1048576].End(xlUp).Row).Value)
If Not IsArray(ListClients) Then ReDim ListClients(1 To 1): ListClients(1) = Sheets(2).Range("B1")
ComboBox_client.List = ListClients
ComboBox_ref.MatchEntry = fmMatchEntryNone
ListRefs = Application.Transpose(Sheets("ref").Range("A1:A" & Sheets("ref").[A1048576].End(xlUp).Row).Value)
If Not IsArray(ListRefs) Then ReDim ListRefs(1 To 1): ListRefs(1) = Sheets("ref").Range("A1")
ComboBox_ref.List = ListRefs
Me.ComboBox_ref.SetFocus
End Sub