// JavaScript Document
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;     
      }     
  }