屏蔽右键菜单代码（所有浏览器）

<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; 
    } 
}
</script>