Support for wp contstants

advanced-wp-columns/trunk/assets/js/plugins/columns.js

onclick: function() {
                            tb_show('Advanced WP Columns', '../wp-content/plugins/advanced-wp-columns/assets/js/plugins/views/columns.html?TB_iframe=1&width=960');
                        }

Not sure what the correct way to do it is but maybe create a variable in function to to load earlier or something and then later access it with tb_show….

var url = "<?php echo plugins_url() ?>/advanced-wp-columns/assets/js/plugins/views/columns.html?TB_iframe=1&width=960";

onclick: function() { tb_show('Advanced WP Columns", url); }