usually I\'ve had success to install Jquery validation on My HTML. BUt now, I Confuses with validation that not working well.
This the HTML script
Your html is invalid, table cannot have form as a child, so make the form as the parent of table
<form method="post" action="undian.php" id="FORM_UNDIAN">
<table border="0" align="center">
<tr>
<td>Nama :</td>
<td>
<input type="text" name="NAMA" placeholder="Nama" class="inputs" />
</td>
</tr>
<tr>
<td>Email :</td>
<td>
<input type="text" name="EMAIL" placeholder="Email" class="inputs" />
</td>
</tr>
<tr>
<td>Kota :</td>
<td>
<div class="ui-widget">
<input type="text" name="KOTA" placeholder="Kota" id="tags" class="inputs" />
</div>
<!--end of ui-widget-->
</td>
</tr>
<tr>
<td colspan="2" align="right">
<input type="submit" name="OKE" value="Submit" id="submit1" />
</td>
</tr>
</table>
</form>
Demo: Fiddle
Look at your html the input elements are not within the form element