使用复选框从DB表中删除多行

这是我的代码-

<?php
$host = "localhost"; // Host name
$username = ""; // Mysql username
$password = ""; // Mysql password
$db_name = "test"; // Database name
$tbl_name = "test_mysql"; // Table name
// Connect to server and select databse.
mysql_connect("$host", "$username", "$password") or die("cannot connect");
mysql_select_db("$db_name") or die("cannot select DB");
$sql = "SELECT * FROM $tbl_name";
$result = mysql_query($sql);
$count = mysql_num_rows($result);
?>
<table width="400" border="0" cellspacing="1" cellpadding="0">
    <tr>
        <td>
            <form name="form1" method="post" action="">
                <table width="400" border="0" cellpadding="3" cellspacing="1" bgcolor="#CCCCCC">
                    <tr>
                        <td bgcolor="#FFFFFF">&nbsp;</td>
                        <td colspan="4" bgcolor="#FFFFFF"><strong>Delete multiple rows in mysql</strong></td>
                    </tr>
                    <tr>
                        <td align="center" bgcolor="#FFFFFF">#</td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Id</strong></td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Name</strong></td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Lastname</strong></td>
                        <td align="center" bgcolor="#FFFFFF"><strong>Email</strong></td>
                    </tr>
                    <?php
                    while ($rows = mysql_fetch_array($result)) {
                        ?>
                        <tr>
                            <td align="center" bgcolor="#FFFFFF"><input name="checkbox[]" type="checkbox"
                                                                        id="checkbox[]" value="<? echo $rows['id']; ?>">
                            </td>
                            <td bgcolor="#FFFFFF"><? echo $rows['id']; ?></td>
                            <td bgcolor="#FFFFFF"><? echo $rows['name']; ?></td>
                            <td bgcolor="#FFFFFF"><? echo $rows['lastname']; ?></td>
                            <td bgcolor="#FFFFFF"><? echo $rows['email']; ?></td>
                        </tr>
                        <?php
                    }
                    ?>
                    <tr>
                        <td colspan="5" align="center" bgcolor="#FFFFFF"><input name="delete" type="submit" id="delete"
                                                                                value="Delete"></td>
                    </tr>
                    <?
                    // Check if delete button active, start this
                    if ($delete) {
                        for ($i = 0; $i < $count; $i++) {
                            $del_id = $checkbox[$i];
                            $sql = "DELETE FROM $tbl_name WHERE id='$del_id'";
                            $result = mysql_query($sql);
                        }
                        // if successful redirect to delete_multiple.php
                        if ($result) {
                            echo "<meta http-equiv="refresh" content="0;URL = delete_multiple . php">";
    }
                    }
                    mysql_close();
                    ?>
                </table>
            </form>
        </td>
    </tr>
</table>

我想要的是表的数据行，其复选框被选中，要在单击"删除"按钮时从数据库中删除。

我试过这些，但效果不好。

请就以上代码向我建议如何删除所选行从DB中，单击Delete按钮。