javascript 屏蔽F5，BackSpace等各种按键

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;

Java代码  

function document.onkeydown()
{
   if ((event.keyCode==8)   ||                  //屏蔽退格删除键
       (event.keyCode==116)||                  //屏蔽 F5 刷新键
       (event.ctrlKey && event.keyCode==82)){ //Ctrl + R
      event.keyCode=0;
      event.returnValue=false;
      }
}

一，js屏蔽浏览器（IE和FireFox）的刷新功能 

document.onkeydown=function()
{
  if ((window.event.keyCode==116)|| //屏蔽 F5
      (window.event.keyCode==122)|| //屏蔽 F11
      (window.event.shiftKey && window.event.keyCode==121) //shift+F10
     )
     {
          window.event.keyCode=0;
          window.event.returnValue=false;
     }
  if ((window.event.altKey)&&(window.event.keyCode==115))
     {
         //屏蔽Alt+F4
         window.showModelessDialog("about:blank","","dialogWidth:1px;dialogheight:1px");
         return false;
     }
}

二，js屏蔽浏览器右键功能 

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