$(document).ready(function(){
    // Initialize the editable-table functionality
    $('#usertable').editableTableWidget();

    $('#btnnewuser').click(function() {
        var newUser = 'User' + String(Math.floor(Math.random() * Math.floor(9999))).padStart(4, '0');

        $('#usertable tbody').append($('<tr><td>' + newUser + '</td><td>User</td><td class="immutable"><a href="?">0</a></td></tr>'));
        // Call `editableTableWidget()` again to include the newly added `<tr>`
        //   To prevent recreating multiple new editors; reference the already existing `<input>`
        $('#usertable').editableTableWidget({editor: $('#editor')});
    });
});