IsDBNull

        If IsDBNull(DataGridView1.CurrentRow.Cells(0).Value) Then
            txtKd_Aktiva.Text = ""
            txtKd_Dept.Text = ""

        Else
            txtKd_Aktiva.Text = DataGridView1.CurrentRow.Cells(0).Value
            txtKd_Dept.Text = DataGridView1.CurrentRow.Cells(1).Value
        End If