//$("#content").setIframeHeight();
(function($){
  jQuery.fn.setIframeHeight=function(){
    var $_self=this;
    $_self[0].onload=function(){
      //下面2种获取高度的方式都可
      //var height1=$(window.frames[$_self[0].name].document.body).height();
      var height=$_self.contents().find("body").height();
      if(height<$_self.height())
        $_self.height($_self.height());
      else
        $_self.height(height);
    }
    return this;
  }
})(jQuery);