function MultiSelector(list_target, max, file_label) {
    var _base = this;

    this.list_target = list_target;
    this.id = 0;
    this.max = max || -1;
    this.file_label = file_label;

    this.addElement = function (element) {
        if (element.tagName === 'INPUT' && element.type === 'file') {
            element.multi_selector = _base;
            element.onchange = function () {
                var i = 0;
                var sErrMsg = "첨부파일 개수는 [" + _base.max + "]까지 첨부할 수 있습니다!";
                var files_length = 1;

                if (typeof element.files !== "undefined") {
                    files_length = element.files.length;
                }

                if (_base.max < files_length) {
                    element.value = "";
                    alert(sErrMsg);

                    while (_base.list_target.firstChild) {
                        _base.list_target.removeChild(_base.list_target.firstChild);
                    }

                    return;
                }

                if (document.getElementById("egov_file_view_table") != null) {
                    var sum = files_length + document.getElementById("egov_file_view_table")
                        .getElementsByTagName("img").length;

                    if (_base.max < sum) {
                        element.value = "";
                        alert(sErrMsg);
                        return;
                    }
                }

                if (files_length > 0) {
                    while (_base.list_target.firstChild) {
                        _base.list_target.removeChild(_base.list_target.firstChild);
                    }
                }

                for (i; i < files_length; i++) {
                    _base.addListRowNew(element, i);
                }
            };
            _base.current_element = element;
        } else {
            alert('Error: not a file input element');
        }
    };

    this.addListRowNew = function (element, i) {
        var new_row = document.createElement('div');
        new_row.className = "file_add_" + i;
        new_row.innerHTML = "<span>" + element.files[i].name
            + "</span>&nbsp;&nbsp;";
        _base.list_target.appendChild(new_row);
    };
}

var EgovMultiFilesChecker = {
    getFileExtension: function (filename) {
        if (filename == null) return "";
        var __fileLen = filename.length;
        var __lastDot = filename.lastIndexOf('.');
        if (__lastDot < 0) return "";
        var __fileExt = filename.substring(__lastDot, __fileLen).toLowerCase();
        return __fileExt;
    },

    checkExtensions: function (fileObjId, allowTypes) {
        if (document.getElementById(fileObjId) == null) return false;

        if (typeof document.getElementById(fileObjId).files !== "undefined") {
            return this.checkExtensionsHTML5(fileObjId, allowTypes);
        } else {
            return this.checkExtensionsOldIE(fileObjId, allowTypes);
        }
    },

    checkExtensionsHTML5: function (fileObjId, allowTypes) {
        var __filelen = document.getElementById(fileObjId).files.length;
        var __fileObjs = document.getElementById(fileObjId).files;
        if (__filelen === 0) return true;
        for (var i = 0; i < __fileObjs.length; i++) {
            var __fileObj = __fileObjs[i];
            var __fileExt = this.getFileExtension(__fileObj.name);
            if (__fileExt === "" || (allowTypes + ".").indexOf(__fileExt + ".") < 0) {
                alert("허용되지 않는 확장자 입니다.[" + __fileExt + "]");
                return false;
            }
        }
        return true;
    },

    checkExtensionsOldIE: function (fileObjId, allowTypes) {
        var __filelPath = document.getElementById(fileObjId).value;
        var __fileExt = this.getFileExtension(__filelPath);
        if (__fileExt === "" || (allowTypes + ".").indexOf(__fileExt + ".") < 0) {
            alert("2.허용되지 않는 확장자 입니다.[" + __fileExt + "]");
            return false;
        }
        return true;
    },

    checkFileSize: function (fileObjId, allowSize) {
        if (document.getElementById(fileObjId) == null) return false;
        if (typeof document.getElementById(fileObjId).files !== "undefined") {
            return this.checkFileSizeHTML5(fileObjId, allowSize);
        } else {
            return this.checkFileSizeOldIE(fileObjId, allowSize);
        }
    },

    checkFileSizeHTML5: function (fileObjId, allowSize) {
        var __filelen = document.getElementById(fileObjId).files.length;
        var __fileObjs = document.getElementById(fileObjId).files;
        if (__filelen === 0) return true;
        for (var i = 0; i < __fileObjs.length; i++) {
            var __fileObj = __fileObjs[i];
            if (__fileObj.size > allowSize) {
                alert("허용되지 않는 파일 사이즈 입니다.[" + __fileObj.name
                    + " : " + __fileObj.size + " bytes / " + allowSize + " bytes]");
                return false;
            }
        }
        return true;
    },

    checkFileSizeOldIE: function (fileObjId, allowSize) {
        alert('구형 브라우저에서는 파일 사이즈 체크를 할수 없습니다.');
        return true;
    }
};