Edit in JSFiddle

Result
HTML
JavaScript
CSS

<body>
<table id="t1" align="center" border="1" width="30%">
     <tr>
     <th>Emp ID</th>
     <th>Emp Name</th>
     </tr>
     <tr>
     <td>1001</td>
     <td>Santi Cazorla</td>
     </tr>
     <tr>
     <td>1002</td>
     <td>Thomas Vermaelen</td>
     </tr>
     <tr>
     <td>1003</td>
     <td>Nacho Monreal</td>
     </tr>
     <tr>
<td align="center" colspan="2"><input type="button" id="b1" value="Press" 
onclick="createCaption()">
</td>
</tr>
     </table>
</body>

function createCaption()
{
var c=document.getElementById("t1").createCaption();
c.innerHTML="EmployeeInfo";
}

caption
{
font-family:comic sans ms;
color:green;
}
&lt;style&gt;