echo
"<tr>
<td><p3></p3></td>
<td><a href='../doctor/files/",mysql_result($result,$i,file_name),"'>",mysql_result($result,$i,file_name),"</a></td>
<td>",mysql_result($result,$i,uploaded_on),"</td>
<td>",mysql_result($result,$i,username_add),"</td>
<td> <img src='http://chart.apis.google.com/chart?cht=qr&chs=150x150&chl=' . htmlentities(urlencode(mysql_result($result,$i,file_name)) . ''> </td>
</tr>";
echo "</table>";
.intro-img {
display: block;
position: absolute;
top: 76px;
text-align: center;
margin: 0px auto;
left: 0px;
right: 0px;
}
<img src="img/background-photo.jpg" width="1200" height="508">