Fish inventory system using C#.net

This tutorial will teach you  to make a small Fish shop Inventory  system using c#.net. The following  system will use to manage the Fish shop.

paste the code inside the ok button

  string status = txtstatus.SelectedItem.ToString();
  double qty = double.Parse(txtqty.Text);

            if(status.Equals("KG"))
            {
                double tot = qty * 140;
                txtbill.Text = tot.ToString();
            }
            else
            {
                double tot = qty/1000 * 140;
                txtbill.Text = tot.ToString();
            }

i have attached the video link below. which will do this tutorials step by step.