我有一个列表是通过查询数据库动态生成的,代码是这样的
 <ol id="camera_list_ul"><img src="/img/camera_list.png" />CameraList
                    <?php
                        require ('mysql_connect.php'); 
                        $dbc = mysql_connect(DB_HOST,DB_USER,DB_PASS) OR die('Could not connect to MySQL: ' . mysqli_connect_error());
                        mysql_select_db('mizuma') or die('Could Not Select DataBase');
                        
                        $sql = "SELECT * FROM camera_list";
                        $result = mysql_query($sql);                         if ($result)
                        {                            
                            while($row = mysql_fetch_array($result,MYSQL_ASSOC))
                            {                               
                                echo '<li onclick="show(this.value)"><img src="/img/camera_stop.png" />' . $row['cam_id'].'-'. $row['name'].'</li>';
                            }
                        }                        
                    ?>                   
                </ol>    
每个li都添加了onclick事件,然后在javascript里写了这个函数
function show(str)
            {
             window.alert(str);
            }当我点击li项后,弹出的value一直都是0,请问怎么才能获得这个列表项的value?