Edit in JSFiddle

(function () {
    if (window.addEventListener) {
        window.addEventListener('load', run, false);
    } else if (window.attachEvent) {
        window.attachEvent('onload', run);
    }

    function run() {
        var t = document.getElementById('myTable');
        t.onclick = function (event) {
            event = event || window.event; //IE8
            var target = event.target || event.srcElement;
            while (target && target.nodeName != 'TR') { // find TR
                target = target.parentElement;
            }
            //if (!target) { return; } //tr should be always found
            var cells = target.cells; //cell collection - https://developer.mozilla.org/en-US/docs/Web/API/HTMLTableRowElement
            //var cells = target.getElementsByTagName('td'); //alternative
            if (!cells.length || target.parentNode.nodeName == 'THEAD') {
                return;
            }
            var f1 = document.getElementById('firstname');
            var f2 = document.getElementById('lastname');
            var f3 = document.getElementById('age');
            var f4 = document.getElementById('total');
            var f5 = document.getElementById('discount');
            var f6 = document.getElementById('diff');
            f1.value = cells[0].innerHTML;
            f2.value = cells[1].innerHTML;
            f3.value = cells[2].innerHTML;
            f4.value = cells[3].innerHTML;
            f5.value = cells[4].innerHTML;
            f6.value = cells[5].innerHTML;
            //console.log(target.nodeName, event);
        };
    }

})();

<form action="" method="" >
  
<table id="form" cellspacing="1">
  <tr width="100%"><th colspan="2" >php listview - anichandran</th></tr>
   <tr>
   <td id="left">  Firstname is:</td>
  <td><input type="text" id="firstname" /></td>
   </tr>
  <tr>
   <td id="left">Lastname is:</td>
  <td><input type="text" id="lastname" /></td>
   </tr>
   <tr>
   <td id="left">Age is:</td>
  <td><input type="text" id="age" /></td>
   </tr>
   <tr>
   <td id="left">Total is:</td>
  <td><input type="text" id="total" /></td>
   </tr>
     <tr>
   <td id="left">Discount is:</td>
  <td><input type="text" id="discount" /></td>
   </tr>
   <tr>
   <td id="left">Diff is:</td>
  <td><input type="text" id="diff" /></td>
   </tr>
  <tr><td></td>
  <td colspan="2"><input type="submit" value="Submit"  /><input type="submit" value="Reset" /></td>
   </tr>
  </table>

</form>


<table id="myTable" cellspacing="1" style="height:15px;overflow:scroll;">
    <thead>
        <tr>
            <th>first name</th>
            <th>last name</th>
            <th>age</th>
            <th>total</th>
            <th>discount</th>
            <th>diff</th>
        </tr>
    </thead>
        <tr>
            <td>peter</td>
            <td>parker</td>
            <td>28</td>
            <td>9.99</td>
            <td>20.3%</td>
            <td>+3</td>
        </tr>
        <tr>
            <td>john</td>
            <td>hood</td>
            <td>33</td>
            <td>19.99</td>
            <td>25.1%</td>
            <td>-7</td>
        </tr>
        <tr>
            <td>clark</td>
            <td>kent</td>
            <td>18</td>
            <td>15.89</td>
            <td>44.2%</td>
            <td>-15</td>
        </tr>
        <tr>
            <td>bruce</td>
            <td>almighty</td>
            <td>45</td>
            <td>153.19</td>
            <td>44%</td>
            <td>+19</td>
        </tr>
        <tr>
            <td>bruce</td>
            <td>evans</td>
            <td>56</td>
            <td>153.19</td>
            <td>23%</td>
            <td>+9</td>
        </tr>
  <tr>
            <td>clark</td>
            <td>kent</td>
            <td>18</td>
            <td>15.89</td>
            <td>44.2%</td>
            <td>-15</td>
        </tr>
        <tr>
            <td>bruce</td>
            <td>almighty</td>
            <td>45</td>
            <td>153.19</td>
            <td>44%</td>
            <td>+19</td>
        </tr>
        <tr>
            <td>bruce</td>
            <td>evans</td>
            <td>56</td>
            <td>153.19</td>
            <td>23%</td>
            <td>+9</td>
        </tr>
</table>    

th,tr
{
    width:100px;
    height:10px;
    background:#ddd;
 }
th
{
    background:green;
}
#form,#myTable
{
 width:100%;
 background:#ddd;  
 margin:0px auto;
  border:1px solid orange;
}
input
{
 background:#fff; 
 border:1px solid ddd;
}
input[type="submit"]
{
 background:eee; 
 border:1px solid orange;
  font-weight:bold;
  border-radius:5px;
 color:red;
}
#left
{
  text-align:right;
}