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>