private void btnIzmjeni_Click(object sender, EventArgs e)
        {
            frmNovaUsluga izmjena = new frmNovaUsluga(_UslugaId)
            {
                Parent = Parent
            };

            izmjena.Show();
        }
        private void btnNovaUsluga_Click(object sender, EventArgs e)
        {
            frmNovaUsluga novaUsluga = new frmNovaUsluga(null)
            {
                Parent = this
            };

            novaUsluga.Show();
        }