php下拉菜单放在html表中

i have done this dropdown menu which takes the distinct POS from my database. and it is displayed out as how the attached picture shows.

however i want the php dropdown menu to be placed in the html table instead. as shown in the 2nd picture. so i can update the particular field. but i don't know how to do it, do help! :)

<td><input type="text" name="POS" placeholder="POS" required />

<?php
mysql_connect('localhost', 'root', '');
mysql_select_db('ishop');

$sql = "SELECT DISTINCT POS FROM tbl_st";
$result = mysql_query($sql);

echo "<select name='POS'>";
while ($row = mysql_fetch_array($result)) {
    echo "<option value='" . $row['POS'] ."'>" . $row['POS'] ."</option>";
}
echo "</select>";
?>


</td>
</tr>

try this

<td><input type="text" name="POS" placeholder="POS" required />

    <?php
        mysql_connect('localhost', 'root', '');
        mysql_select_db('ishop');

        $sql = "SELECT DISTINCT POS FROM tbl_st";
        $result = mysql_query($sql);

        echo "<select name='POS'>";
        while ($row = mysql_fetch_array($result))
        {
            ?>

            <option value="<?php echo $row['POS'] ?>"><?php echo  $row['POS'] ?></option>;
        <?php
        }
        echo "</select>";
    ?>


</td>