Apply CSS to jQuery Dialog Buttons

I’m reposting my answer to a similar question because no-one seems to have given it here and it’s much cleaner and neater:

Use the alternative buttons property syntax:

$dialogDiv.dialog({
    autoOpen: false,
    modal: true,
    width: 600,
    resizable: false,
    buttons: [
        {
            text: "Cancel",
            "class": 'cancelButtonClass',
            click: function() {
                // Cancel code here
            }
        },
        {
            text: "Save",
            "class": 'saveButtonClass',
            click: function() {
                // Save code here
            }
        }
    ],
    close: function() {
        // Close code here (incidentally, same as Cancel code)
    }
});