<table class="w3-table-all w3-margin-top" id="myTable">
<tr>
  <th style="width:20%;">Vendor Picture Path</th>
  <th style="width:20%;">Vendor Heading</th>
  <th style="width:20%;">Vendor Adding Date</th>
  <th style="width:20%;">Vendor Body</th>
  <th style="width:10%;">Add A Course</th>
  <th style="width:10%;">Add A Batch</th>
</tr>
<?php

mysql_connect("hist", "user", "pass")or die("cannot connect to server");
    mysql_select_db("name")or die("cannot select DB");
    $sql = "query";
    $result = mysql_query($sql);

    while($row=mysql_fetch_assoc($result))
    {
         echo '<tr>
         <td><div style="width:100%;height: 60px;margin: 0;padding: 0;overflow-y: scroll">'.$row["pic_path"].'</div></td>
         <td><div onclick="getval(this)" class="cventablehead" id="ventablehead" style="width:100%;height: 60px;margin: 0;padding: 0;overflow-y: scroll; cursor: pointer; color:red;">'.$row["heading"].'</div></td>
         <td>'.$row["adding_date"].'</td>
         <td><div style="width:100%;height: 60px;margin: 0;padding: 0;overflow-y: scroll">'.$row["body"].'</div></td>
         <td><button onclick="addcourse(this)">Add</button></td>
         <td><button onclick="addbatch(this)">Add</button></td>
         </tr>';
    }
?>
  </table>
</div>

function addcourse(obj)
  {
    alert(obj.querySelector('#ventablehead').innerHTML);
  }

function addcourse(obj)
  {
    alert(obj.getElementsByClassName("cventablehead").innerHTML);
  }

function addcourse(obj)
  {
    alert(obj.getElementsByClassName("cventablehead")[0].innerHTML);
  }