Im view total form
total = harga * unit;
View Sample Images :
http://www.daniweb.com/forums/attachment.php?attachmentid=22008&stc=1&d=1313603319

<table border="1">
<tr>
	<td bgcolor="#6699FF">jenis</td>
	<td bgcolor="#6699FF">harga</td>
    <td bgcolor="#6699FF">unit</td>
    <td bgcolor="#6699FF">total</td>
</tr>
<tr>
	<td><?php
	include"koneksi.php";
	$result = mysql_query("select * from tpintu");
	$jsArray = "var prdName = new Array();\n";
	echo '<select name="prdId" onchange="document.getElementById(\'hargaBarang\').value = prdName[this.value]">';
	while ($row = mysql_fetch_array($result)) {
    echo '<option value="' . $row['jenis_pintu'] . '">' . $row['jenis_pintu'] . '</option>';
    $jsArray .= "prdName['" . $row['jenis_pintu'] . "'] = '" . addslashes($row['harga_pintu']) . "';\n";
	}
	echo '</select>';
	?>
    </td>
    <td>
 	 <input name="hargaBarang" type="text" id="hargaBarang" size="22"/>
  	<script type="text/javascript">
	<?php echo $jsArray; ?>
	</script>
</td>
<td><input type="text" name="textfield" id="textfield"></td>
<td><input type="text" name="textfield2" id="textfield2"></td>
</tr>
<tr>
<td colspan="3" align="right">Total : </td>
<td><input type="text" name="textfield3" id="textfield3"></td>
</tr>
</table>

Thank'z

your link doesn't work, and what is your question.
what do you want to total on this page?
there are no "total = harga * unit;" 'harga' or 'unit' variables on this page at all.
there are no form tags and no submit button on your form.
what is your question, what are you trying to do?