Javascript屏蔽鍵盤的代碼

　　請寫一段Javascript的代碼防止用戶提交表單後刷新網頁（例如按F或按IE上的刷新按鈕）重新提交表單內容頁面提交是在本頁面提交到本頁面大家幫幫忙？

　　下面的代碼只是實現了屏蔽鼠標右鍵Ctrl+nshift+FF刷新退格鍵

　　function KeyDown(){
 //屏蔽鼠標右鍵Ctrl+nshift+FF刷新退格鍵
 //alert(ASCII代碼是+eventkeyCode);
  if ((windoweventaltKey)&&
      ((windoweventkeyCode==)||   //屏蔽 Alt+ 方向鍵 ←
       (windoweventkeyCode==))){  //屏蔽 Alt+ 方向鍵 →
     alert(不准你使用ALT+方向鍵前進或後退網頁！);
     eventreturnValue=false;
     }
  if ((eventkeyCode==)  ||                 //屏蔽退格刪除鍵
      (eventkeyCode==)||                 //屏蔽 F 刷新鍵
      (eventkeyCode==)||                 //屏蔽 F 刷新鍵
      (eventctrlKey && eventkeyCode==)){ //Ctrl + R
     eventkeyCode=;
     eventreturnValue=false;
     }
  if ((eventctrlKey)&&(eventkeyCode==))   //屏蔽 Ctrl+n
     eventreturnValue=false;
  if ((eventshiftKey)&&(eventkeyCode==)) //屏蔽 shift+F
     eventreturnValue=false;
  if (windoweventsrcElementtagName == A && windoweventshiftKey)
      windoweventreturnValue = false;  //屏蔽 shift 加鼠標左鍵新開一網頁
  if ((windoweventaltKey)&&(windoweventkeyCode==)){ //屏蔽Alt+F
      windowshowModelessDialog(about:blankdialogWidth:px;dialogheight:px);
      return false;}
}

From:http://tw.wingwit.com/Article/program/Java/JSP/201311/19708.html