Javascript禁止页面刷新、退后

<script   language="javascript">      
//禁止用F5键      
function   document.onkeydown()      
{      
          if   (   event.keyCode==116)      
          {      
                  event.keyCode   =   0;      
                  event.cancelBubble   =   true;      
                  return   false;      
          }      
}      
       
//禁止右键弹出菜单      
function   document.oncontextmenu()      
{      
      return   false;      
}      
       
//下面代码实现全屏显示      
function   window.onload(){      
      var   Request   =   new   Array();//保存参数      
      var   s   =   location.search.substring(1);      
      if   (s   &&   s!=""){      
      var   list   =   s.split("&");      
for   (var   i=0;   i   <   list.length;   i++){      
var   pair   =   list[i].split("=");      
if   (pair[0]   &&   pair[0]   !=""){      
Request[unescape(pair[0])]   =   unescape(pair[1]);      
}      
}      
      }      
       
      var   fullscreen=Request["fullscreen"];      
      if(fullscreen!="yes"){      
      var   file   =self.location;      
      var   a   =   window.open("about:blank","","fullscreen=yes")      
      self.opener=null      
      self.close()      
      a.location=file   +   "?fullscreen=yes";      
      }      
}      
</script>  
 
 
<script language="Javascript"><!--    
//屏蔽鼠标右键、Ctrl+N、Shift+F10、F11、F5刷新、退格键    
//Author: meizz(梅花雨) 2002-6-18    
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;    
}    
/* 注：这还不是真正地屏蔽 Alt+ 方向键，   
因为 Alt+ 方向键弹出警告框时，按住 Alt 键不放，   
用鼠标点掉警告框，这种屏蔽方法就失效了。以后若   
有哪位高手有真正屏蔽 Alt 键的方法，请告知。*/    
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>