test 1 aja

   <table>
      <tr>
        <td>
          <input id='harga_1' value=120 />
        </td>
        <td>
          <input id='jml_1' value=21 />
        </td>
        <td>
          <input id='tot_1' />
        </td>
      </tr>
<?
for($i=2;$i<11;$i++)
{?>
      <tr>
        <td>
          <input id='harga_<?=$i;?>' />
        </td>
        <td>
          <input id='jml_<?=$i;?>' />
        </td>
        <td>
          <input id='tot_<?=$i;?>' />
        </td>
      </tr>
<?
}
?>
    </table>
<input id='total_all' >
<script>
var int=self.setInterval(function(){hitung()},1500);
function hitung()
{
var i=1;done=1
    while(i<100)
    {

        harga="#harga_"+i;
        jml="#jml_"+i;
        tot="#tot_"+i;
        //console.log(i+"="+$(harga).val());
        if($(harga).val()!=undefined)
        {
            subtot=$(harga).val() * $(jml).val();
            $(tot).val(subtot);
            i++;
        }else{
            i=200;

        }
    }
}


var int=self.setInterval(function(){clock()},1000);
function clock()
  {
  var d=new Date();
  var t=d.toLocaleTimeString();
  document.getElementById("clock").value=t;
  }
</script>