[javascript] How get total sum from input box values using Javascript?

Try this:

function add() 
{
  var sum = 0;
  var inputs = document.getElementsByTagName("input");
  for(i = 0; i <= inputs.length; i++) 
  {
   if( inputs[i].name == 'qty'+i) 
   {
     sum += parseInt(input[i].value);
   }
  }
  console.log(sum)

}