Fish Inventory Shop using Java

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

paste the code inside the ok button

 String item = txtstatus.getSelectedItem().toString();
 double fish = Double.parseDouble(txtqty.getText());
          
          if(item.equals("KG"))
          {
          double cal = (fish * 140) ; 
          txtbill.setText(String.valueOf(cal));
          
          }
         else
          {
          double cal = (fish/1000 * 140) ; 
          txtbill.setText(String.valueOf(cal));
          }

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