<script> //屏蔽鼠标右键、Ctrl+N、Shift+F10、F11、F5刷新、退格键     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>