how to send data with + in javascript

json_plus

<script type="text/javascript">
$.ajax({
            type: 'POST',
            cache: false,
            data: 'params=' + escape(JSON.stringify(structure)).replace(new RegExp("\\+", "g" ),"%2B"),
            url: '/adm.php/sendregexp',
            success: function(response) {
                var result = jQuery.parseJSON(response);

                if (result.code == 300) {
                    $.each(result.message, function(i, l) {
                        $('#name-' + l).css('border', '1px solid red');
                    });
                } else {
                    alert(result.message);
                }
            }
        });
</script>