Handling data modification - php

Question

I have such a situation. Here is my code =>
while ($data = mysqli_fetch_assoc($result)){
echo "<tr>";
echo "<td><span class='getinfo'>" . $data['username'] . "</span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'>" . $data['email'] . "</span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'>" . $data['rights'] . "</span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'>" . $data['last_seen'] . "</span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'>" . $data['since'] . "</span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'><select name='change_rights'><option value='sel'>* * *</option><option value='null'>0</option><option value='one'>1</option></select></span></td>";
echo "<td></td>";
echo "<td><span class='getinfo'><input type='submit' name='del_user' id='del_user' value='Delete'></span></td>";
echo "</tr>";
}
Like you see , I've made preposition along of data <select> and delete Submit
this is all in one
<form name="" action="" method="post"></form>
Is it possible to make modification with <select> and also delete data from script like this and if it possible how? Or not can advice me how to that?
If I have html form like this =>
<form name="mod" action="default.php" method="post">
<input type="checkbox" name="mod[]" id="mod1">
<input type="checkbox" name="mod[]" id="mod2">
<input type="submit" name="ok" value="ok">
</form>
and php =>
if (isset($_POST['ok'])){
if ($_POST['mod']=="mod1"){
echo "one";
} else {
echo "two";
}
}
(I've never user checkbox with php and I have not know it well)
something is not going well, what is wrong here?

Answer 1

This does not look that good. Try using seperate forms for each entry and add a hidden field to it which holds the identifier. Another solution: add checkboxes to each entry and use a single form with only one submit button