스마트에디터 이미지만 허용합니다 경고창 뜨는데가

_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;                        $img = "<img src='"+file.url+"' width='"+ret['width']+"' height='"+ret['height']+"' class='pre_thumb' />";                                            }                    if (!index) {                        node                            .prepend('<br>')                            .prepend($img);                        if(size_text){                            node.append('<br>')                            .append($('<span/>').text(size_text))                        }                    }                node.appendTo(data.context);                node.find(".delete_img").on("click", othis._delete);            });            $(othis.dreg_area_list).sortable('refresh');        },