change line 151:
<td class="WADADataTableCell"><input type="text" name="ContactDOB" id="ContactDOB" value="<?php echo(str_replace('"', '"', $row_WADAtblcontacts['ContactDOB'])) ?>" size="32" /></td>
to:
<td class="WADADataTableCell"><input type="text" name="ContactDOB" id="ContactDOB" value="<?php echo(date("d-m-Y", strtotime($row_WADAtblcontacts['ContactDOB']))) ?>" size="32" /></td>