javascript实现禁止右键和F12查看源代码

function click(e) {
                                if (document.all) {
                                        if (event.button==2||event.button==3) { 
                                                alert("欢迎光临寒舍，有什么需要帮忙的话，请与站长联系！谢谢您的合作！！！");
                                                oncontextmenu='return false';
                                        }
                                }
                                if (document.layers) {
                                        if (e.which == 3) {
                                                oncontextmenu='return false';
                                        }
                                }
                        }
                        
                        if (document.layers) {
                                document.captureEvents(Event.MOUSEDOWN);
                        }
                        document.onmousedown=click;
                        document.oncontextmenu = new Function("return false;")

                        document.onkeydown =document.onkeyup = document.onkeypress=function(){ 
                                if(window.event.keyCode == 123) { 
                                        window.event.returnValue=false;
                                        return(false); 
                                } 
                        }