function jb51tuitan(){ if (getCookie('jb51popped')==''){ //要执行的代码或一些操作 setCookie("jb51popped","ok"); //写入cookies表示已经执行过了。  alert("ok"); } } jb51tuitan() function setCookie(name, value)     {     var argv = setCookie.arguments;     var argc = setCookie.arguments.length;     var expires = (argc > 2) ? argv[2] : null;     if(expires!=null)     {         var LargeExpDate = new Date ();         LargeExpDate.setTime(LargeExpDate.getTime() + (expires*1000*3600*24));     }     document.cookie = name + "=" + escape (value)+((expires == null) ? "" : ("; expires=" +LargeExpDate.toGMTString())); } function getCookie(Name) {     var search = Name + "="     if(document.cookie.length > 0)     {         offset = document.cookie.indexOf(search)         if(offset != -1)         {             offset += search.length             end = document.cookie.indexOf(";", offset)             if(end == -1) end = document.cookie.length             return unescape(document.cookie.substring(offset, end))          }     else return ""      } }