How to limit checkbox selection in PHP? - php

Question

So far I have been able to get data from MYSQL and display it as a checklist using PHP and HTML. Now I would like to limit the number of checkboxes that can be selected at a time. Javascript doesn't seem to be working with my PHP code.
EDIT: I've included my JScript below which is currently not workng. This JScript only works when I use it with manually created html checklists but not the one I have made below using MYSQL data. How can I fix my Javascript part so this works?
Here is my code:
<?php
$username = "root";
$password = "test";
$hostname = "localhost";
$dbname = "major_degrees";
$str='';
// Create connection
$conn = new mysqli($hostname, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT degree_name FROM majors";
$result = $conn->query($sql);
$out = '';
$cnt = 0;
if ($result->num_rows > 0) {
// output data of each row
while($row = $result->fetch_assoc()) {
$cnt++;
$out .= '<input id="cb_' .$cnt. '" class="someclass" type="checkbox" />' .$row['degree_name']. '<br/>';
}
echo $out;
}
$conn->close();
?>
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<meta charset=utf-8 />
<script>
$out.on("click", ":checkbox", function(event){
$(":checkbox:not(:checked)", this.form).prop("disabled", function(){
return $(this.form).find(":checkbox:checked").length == 2;
});
});
</script>

Answer 1

try this:
<script>
$(".someclass").change(function() {
var count = $(".someclass:checked").length; //get count of checked checkboxes
if (count > 3) {
alert("Only 3 options allowed..!");
$(this).prop('checked', false); // turn this one off
}
});
</script>