document.onselectstart =function() {return   false;}           // 防选择    
document.oncopy        =function() {return   false;}          // 防复制
document.oncut         =function() {return   false;}          // 防剪贴
document.onbeforecopy  =function() {return   false;} 
document.ondragstart   =function() {return   false;}          //防拖动
document.oncontextmenu =function() {return   false;}          //防右键
document.onmouseup     =function() {document.selection.empty();}  
document.onselect      =function() {document.selection.empty();}
document.oncopy        =function() {document.selection.empty();}  
document.onmousedown   =function() {if (event.button!==1){alert('禁止操作');}}
document.onkeydown     =function() {alert("禁止操作");event.keyCode=0;event.returnValue=false;} 

//防键盘操作  

  
// 屏蔽PrintScreen  

  function   testclip(){  
  try   {  
  if(clipboardData.getData("Text")||clipboardData.getData("HTML")||clipboardData.getData("URL"))   //检测系统内存  
  {  
  null;          //不为图像则保留内存  
  }  
  }  
  catch(e){  
  clipboardData.setData("Text","")//清空内存  
  }  
  setTimeout("testclip()",500)  
  }  
   
  //页面加载启动区
    
  testclip();//不停清空剪贴板