js 控制鼠标右键不可使用

if (window.Event){document.captureEvents(Event.MOUSEUP); } function nocontextmenu() { event.cancelBubble = true;event.returnValue = false; return false; } function norightclick(e) { if (window.Event) { if (e.which == 2 || e.which == 3) {return false;                         }} else if (event.button == 2 || event.button == 3) { event.cancelBubble = true event.returnValue = false; return false; } } document.oncontextmenu = nocontextmenu; // for IE5+ document.onmousedown = norightclick; // for all others