js禁止右键菜单代码、禁止复制粘贴代码

    <script type="text/javascript">
        //屏蔽右键菜单
        document.oncontextmenu = function (event) {
            if (window.event) {
                event =
                    window.event;
            } try {
                var the = event.srcElement; if (!((the.tagName == "INPUT" && the.type.toLowerCase() ==
                    "text") || the.tagName == "TEXTAREA")) { return false; } return true;
            } catch (e) {
                return false;
            }
        }
        //屏蔽粘贴
        document.onpaste = function (event) {
            if (window.event) { event = window.event; } try {
                var the =
                    event.srcElement; if (!((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName ==
                        "TEXTAREA")) { return false; } return true;
            } catch (e) { return false; }
        }
        //屏蔽复制
        document.oncopy = function (event) {
            if (window.event) { event = window.event; } try {
                var the = event.srcElement; if (!((the.tagName == "INPUT"
                    && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; } return true;
            } catch (e) {
                return false;
            }
        }
        //屏蔽剪切
        document.oncut = function (event) {
            if (window.event) { event = window.event; } try {
                var
                    the = event.srcElement; if (!((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName ==
                        "TEXTAREA")) { return false; } return true;
            } catch (e) { return false; }
        }
        //屏蔽选中
        document.onselectstart = function (event) {
            if (window.event) { event = window.event; } try {
                var the = event.srcElement; if (!
                    ((the.tagName == "INPUT" && the.type.toLowerCase() == "text") || the.tagName == "TEXTAREA")) { return false; }
                return true;
            } catch (e) { return false; }
        }
    </script>