java code for simple inventory system

This tutorial will teach Chicken Shop Inventory Management using Java step by step. Paste the Code inside the Cal Button double qty; double cal; qty = Double.parseDouble(txtqty.getText()); if(cboption.getSelectedItem().equals(“Gr”)) { cal = 500 * qty/1000; //Gr Calculation } else { cal = 500 * qty; //Kg Calculation } txttot.setText(Double.toString(cal)); i have attached the video link below.