问题与更新DOM之后触发插件JS操作有关.我在插件的js源上发现该动作是由Footnotes.Setup()触发的，因此我将其添加到了ajax加载函数中.

So as you said, the problem is related to triggering the plugin JS action after the DOM is updated. I found on the js source of the plugin that the action is triggered by : Footnotes.Setup(), so I added it in the ajax load function.

现在的代码是:

function tab(var)
{
$(document).ready(function(){

    var Tabs = {
        '1' : 'page1.php?p='+var,
        '2' : 'page2.php?p='+var,
        '3' : 'page3.php?p='+var,
        '4' : 'page4.php?p='+var,
        '5' : 'page5.php?p='+var
    }

    $.each(Tabs,function(i,j){
        var tmp = $('<li><a href="" class="tab">'+i+'</a></li>');
        tmp.find('a').data('page',j);
        $('ul.tabContainer').append(tmp);
    })
    var the_tabs = $('.tab');

    the_tabs.click(function(e){

        var element = $(this);

            var bg = element.attr('class').replace('tab','');

        if(!element.data('cache'))
        {   
            $.get(element.data('page'),function(msg){
            $('#contentHolder').html(msg);
            **Footnotes.setup();**
            element.data('cache',msg);
            });
        }

        e.preventDefault();

    })

    the_tabs.eq(0).click();

});   
      return false; 
}