Java - How can I run the javascript in all my html rows : I am creating invoice form, I have written a Java Script to calculate Tax and Discount price as the user the value, But it is just working in one row how can I enable it to work on all the rows 

Javascript[Javascript to calculate discount and tax][1]


[Html form][2]


  [1]: http://i.stack.imgur.com/ZkuWK.jpg
  [2]: http://i.stack.imgur.com/i2IPs.jpg