Javascript执行PHP代码

我有一个PHP web应用程序项目…我想实现一个javascript的onclick代码。例如:当用户点击关注这篇文章…MySQL查询插入到数据库中，用户遵循这个…所以页面被刷新，之后它会显示为following ..需要什么javascript代码来做这个…或者有没有合适的例子?

这里有一个示例代码

     <div id="main_content">

        <?php
        if(isset($_GET['et']))
        {
        $et = $_GET['et'];
        }
        $result = mysql_query("select * from events where event_type =$et") ;
        require_once('queries/category_extract.php') ;
        ?>
        <div id="body_content">
    <div id="event_tag">
        <a><?php echo $cattitle["categ_title"]?>s</a>
    </div>
    <?php
    while($row=mysql_fetch_array($result) )
    {
        require('queries/followers_extract.php') 
        ?>

        <div id="postpreview">
        <div id="postpreview_up">
            <div id="postpreview_up_left">
                    <div id="postpreview_up_left_left">
                        <a>Event Title :</a>
                    </div>
                    <div id="postpreview_up_left_right">
                    <a><?php echo $row["event_title"] ?></a> 
                    </div>
            </div>
              <div id="postpreview_up_right">
                <img src="images/read_more.gif" />
              </div>
        </div>
        <div id="postpreview_bottom">
            <div id="postpreview_bottom_left">
                <div id="postpreview_bottom_left_left">
                <a>Date :</a>
                </div>
                <div id="postpreview_bottom_left_right">
                <a><?php echo $row["event_date"] ?></a>
                </div>
            </div>
        <div id="postpreview_bottom_right">
                <div id="postpreview_bottom_right_left">
                <?php
                if($follower['follower_id'] ==NULL){echo " <img src='images/follow_button.jpg' /> " ; } 
                    else { echo " <img src='images/follow_closed.jpg' /> " ;}
                ?>
                </div>
                <div id="postpreview_bottom_right_right">
                <?php
                if($follower['follower_id'] !=NULL){ echo " <img src='images/following_button.jpg' /> " ; } 
                else { echo " <img src='images/following_Closed.jpg' /> " ;}
                ?>
                </div>
                <div id="postpreview_bottom_right_right">
                <?php
                if($follower['follower_id'] !=NULL){ echo " <img src='images/unfollow_button.jpg' /> " ; } 
                else { echo " <img src='images/unfollow_closed.jpg' />  " ;}
                ?>
                </div>
        </div>
        </div>
        </div>
        <div id="splitter"></div>
        <?php
    }
    ?>
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