论坛回复功能，编辑器里@name后光标定位问题

悬赏园豆：10 [待解决问题]

单击回复按钮后光标在@name的前面请问怎样才能让光标在@name后面

js代码

$('.request-reply').on('click', function () {
        var othis = $(this),
            type = othis.attr('type');
        $('.layui-form .quotepid').val(othis.attr('pid'));
        var val = $(window.frames["LAY_layedit_1"].document).find('body').val();
        var aite = '@' + othis.attr('username').replace(/\s/g, '');
 
         $(window.frames["LAY_layedit_1"].document).find('body').focus()
         $(window.frames["LAY_layedit_1"].document).find('body').append(aite+' ' + val);
         if(val.indexOf(aite) !== -1) return;
         $(window.frames["LAY_layedit_1"].document).find('body').val(aite +' ' + val);

       
    });