禁止复制、右键、F12

document.onkeydown = function(){

    if(window.event && window.event.keyCode == 123) {
        alert("请尊重劳动成果！");
        event.keyCode=0;
        event.returnValue=false;
    }
    if(window.event && window.event.keyCode == 13) {
        window.event.keyCode = 505;
    }
    if(window.event && window.event.keyCode == 8) {
        alert(str+"\n请使用Del键进行字符的删除操作！");
        window.event.returnValue=false;
    }

}


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;
}
}


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;
}
}


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;
}
}