I'm trying to update table I've created, and I can't seem to get it to post the updated values back to the table.  I'm sure it's something basic I'm missing, but it's driving me crazy.  Any ideas?

PHP Code

//Get Records to Display for Data Entry
 $displaystudents = array();

    $sqldisp = "SELECT su.user_lname, su.user_fname, su.user_id, trn.log_date, trn.D1, trn.D2, trn.D3, trn.D4, trn.D5
FROM se_users su JOIN tfk_stu_training trn ON su.user_id = trn.student_id
JOIN tfk_stu_teacher tch ON trn.student_id = tch.student_id
WHERE trn.log_date = '$week_selected ' and tch.teacher_id = '$teacher_id' ORDER BY su.user_lname";


$numrows = $database->database_num_rows($sqldisp);

$rows2 = $database->database_query($sqldisp);

while($row2 = $database->database_fetch_assoc($rows2) ) {

                   $row2['user_lname'] = $row2['user_lname'];
                   $row2['user_fname'] = $row2['user_fname'];
                   $row2['student_id'] = $row2['user_id'];
                   $row2['log_week'] = $row2['log_date'];
                   $row2['D1'] = $row2['D1'];
                   $row2['D2'] = $row2['D2'];
                   $row2['D3'] = $row2['D3'];
                   $row2['D4'] = $row2['D4'];
                   $row2['D5'] = $row2['D5'];
        array_push($displaystudents, $row2);
                 }

//Update Records when Button is Pushed
if ($_POST["Submit"]) {

    for ($i=0; $i<$numrows; $i++)
        {
          // GET POST VARIABLES
  $D1 = $_POST['D1'][$i];
  $D2 = $_POST['D2'][$i];
  $D3 = $_POST['D3'][$i];
  $D4 = $_POST['D4'][$i];
  $D5 = $_POST['D5'][$i];
  $student_id = $_POST['student_id'][$i];
  $log_week = $_POST['log_week'][$i];

        $sqlupd="UPDATE tfk_stu_training SET D1 = '$D1[$i]', D2 = '$D2[$i]', D3 = '$D3[$i]', D4 = '$D4[$i]', D5 = '$D5[$i]'
            WHERE student_id = '$student_id[$i]' AND log_date = '$log_week[$i]'";
            $database->database_query($sqlupd);
            }

}
// ASSIGN VARIABLES AND INCLUDE FOOTER
$smarty->assign('today', $today);
$smarty->assign('error_message', $error_message);
$smarty->assign('teacher_id', $teacher_id);
$smarty->assign('displaystudents', $displaystudents);
$smarty->assign('week_selected', $week_selected);
$smarty->assign('D1', $D1);
$smarty->assign('D2', $D2);
$smarty->assign('D3', $D3);
$smarty->assign('D4', $D4);
$smarty->assign('D5', $D5);
$smarty->assign('student_id', $student_id);
$smarty->assign('log_week', $log_week);[/code]


TPL Code

         <form name="frmInputData" action='user_teacherlogsmine.php' method='POST'>
         <br />
<table width="100%" class='list'>
    <tr>
        <td class='header'>First Name</td>
        <td class='header'>Last Name</td>
        <td class='header'>Monday</td>
        <td class='header'>Tuesday</td>
        <td class='header'>Wednesday</td>
        <td class='header'>Thursday</td>
        <td class='header'>Friday</td>
    </tr>

   {* LIST STUDENTS *}
  {foreach from=$displaystudents[t] item=student}
        <tr>
       <td class="item">{$student.user_lname}</td>
        <td class="item">{$student.user_fname}</td>
        <td class="item"><input name="D1[t]" value="{$student.D1}" size="7"/></td>
        <td class="item"><input name="D2[t]" value="{$student.D2}" size="7"/></td>
        <td class="item"><input name="D3[t]" value="{$student.D3}" size="7"/></td>
        <td class="item"><input name="D4[t]" value="{$student.D4}" size="7"/></td>
        <td class="item"><input name="D5[t]" value="{$student.D5}" size="7"/></td>
       <input type="hidden" name="student_id[t]" value="{$student.student_id}"/>
        <input type="hidden" name="log_week[t]"value="'{$week_selected}'"/>
        </tr>
   {/foreach}

    <tr>
        <td colspan="7" align="right">
            <input type="submit" name="Submit" class="button" value="Update" />
        </td>
</table>
</form>