private void btn_viewbutton_Click(object sender, EventArgs e)
{
int bulbindex = lb_bulblist.SelectedIndex;
if (bulbindex == -1)
{
return;
}
LightBulb currentBulb = bulbList[bulbindex];
int wattage = currentBulb.getWattage();
double cost = currentBulb.getCost();
lbl_watts.Text = "" + wattage;
lbl_cost.Text = "" + cost;
}