document.oncontextmenu = function () {    return false;};document.ondragstart = function () {    return false;};document.onselectstart = function () {    return false;};document.onbeforecopy = function () {    return false;};document.onselect = function () {    document.selection.empty();};document.oncopy = function () {    document.selection.empty();};// document.onmouseup = function () {//     document.selection.empty();// };function DisableF5() {    with (event) {        // F5 and Ctrl+R        if (keyCode == 116 || (ctrlKey && keyCode == 82)) {            event.keyCode = 0;            event.cancelBubble = true;            return false;        }    }}document.onkeydown = DisableF5;