jsp用javascript关于浏览器静止后退，刷新

<script language="javascript" type="text/javascript" defer="defer">
        history.go(1); 
    </script>

<script language="Javascript"><!-- 
function document.oncontextmenu(){event.returnValue=false;}//屏蔽鼠标右键 
function window.onhelp(){return false} //屏蔽F1帮助 
function document.onkeydown() 
{ 
  if ((window.event.altKey)&& 
      ((window.event.keyCode==37)||   //屏蔽 Alt+ 方向键 ← 
       (window.event.keyCode==39)))   //屏蔽 Alt+ 方向键 → 
  { 
     alert("不准你使用ALT+方向键前进或后退网页！"); 
     event.returnValue=false; 
  } 

  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; 
     } 
  if (event.keyCode==122){event.keyCode=0;event.returnValue=false;}  //屏蔽F11 
  if (event.ctrlKey && event.keyCode==78) event.returnValue=false;   //屏蔽 Ctrl+n 
  if (event.shiftKey && event.keyCode==121)event.returnValue=false;  //屏蔽 shift+F10 
  if (window.event.srcElement.tagName == "A" && window.event.shiftKey)  
      window.event.returnValue = false;             //屏蔽 shift 加鼠标左键新开一网页 
  if ((window.event.altKey)&&(window.event.keyCode==115))             //屏蔽Alt+F4 
  { 
      window.showModelessDialog("about:blank","","dialogWidth:1px;dialogheight:1px"); 
      return false; 
  } 
} 
</script> 
<script>
	$(document).ready( function(){
	var userid=document.getElementById('userkey').value;
	if (userid==0)
	{
		window.location.href="../frontuser/frontuser!login.action";
	}
	});
	</script>