php如何获取豆瓣电影评分？

Question

<span class="branch">

    {if:"{playpage:douban}"==""}

    <span class="font-size-12">暂无评分 </span>     

    {elseif:{playpage:douban} == 0}

    <span class="font-size-12">暂无评分 </span>

    {else}{playpage:douban}

    {end if} 

</span>

<script type="text/javascript">

    var str = "{playpage:douban}%" 

    document.getElementById("score").style.width = (str.replace(".", ""))

</script>

以上代码，为什么获取不到豆瓣评分？哪个地方有问题，求解？！