스마트에디터 이미지만 허용합니다 경고창 뜨는데가 채택완료

</p><p>
        _add : function(e, data, preload){
            var othis = this;
            othis._startmodebg();
            data.context = $('<li/>').addClass("sort_list").appendTo(this.dreg_area_list);
            $.each(data.files, function (index, file) {
                if ( !preload && !othis.filter.test(file.type)) {
                    data.context.remove();
                    alert('이미지만 허용합니다.');
                    return true;
                }
                var node = $('<div/>')
                        .append($('<span/>').text(file.name))
                        .append($('<span/>').addClass("delete_img").attr({"data-delete":file.name,"data-url":file.url}).html("<img src='./img/system_delete.png' alt='삭제' title='삭제' >")),
                    $img = "<img src='./img/loading.gif' class='pre_thumb' />",
                    size_text = '';
                    
                    if ( preload && preload != 'swfupload' ){
                        var ret = othis.get_ratio( file.width, file.height ),
                            size_text = file.width+" x "+file.height;
                        $img = "<img src='"+file.url+"' width='"+ret['width']+"' height='"+ret['height']+"' class='pre_thumb' />";
                        
                    }
                    if (!index) {
                        node
                            .prepend('
')
                            .prepend($img);
                        if(size_text){
                            node.append('
')
                            .append($('<span/>').text(size_text))
                        }
                    }
                node.appendTo(data.context);
                node.find(".delete_img").on("click", othis._delete);
            });
            $(othis.dreg_area_list).sortable('refresh');
        }, </p><p>