function getCookie( name ) {      var start = document.cookie.indexOf( name + "=" );      var len = start + name.length + 1;      if ( ( !start ) && ( name != document.cookie.substring( 0, name.length ) ) ) {          return null;      }      if(start == -1) return null;      var end = document.cookie.indexOf( ";", len );      if ( end == -1 ) end = document.cookie.length;      return unescape( document.cookie.substring( len, end ) );  }  var COOKIE_EXPIRES = 0;  //expires：以天为单位  function setCookie( name, value, expires, path, domain, secure) {      var today = new Date();      today.setTime( today.getTime() );      if ( expires ) {          expires = expires * 1000 * 60 * 60 * 24;      }else{          expires = COOKIE_EXPIRES * 1000 * 60 * 60 * 24;      }      var expires_date = new Date( today.getTime() + (expires) );      document.cookie = name+"="+escape( value ) +          ( ( expires ) ? ";expires="+expires_date.toGMTString() : "" ) +           ( ( path ) ? ";path=" + (path||'/') :"") +          ( ( domain ) ? ";domain=" + (domain||location.hostname) : '') +          ( ( secure ) ? ";secure" : "" );  }    function deleteCookie( name, path, domain ) {      if ( getCookie( name ) ) document.cookie = name + "=" +              ( ( path ) ? ";path=" + path : ";path=" + '/') +              ( ( domain ) ? ";domain=" + domain : "") +              ";expires=Thu, 01-Jan-1970 00:00:01 GMT";  }