js嵌套php

<?php $userid = 1;?> //此处userid是调取过来的，我是为了让你们明白给它赋值了；javascript

<a id="denglu"">我要投诉</a>php

<script type="text/javascript">
    var btn = document.getElementById('denglu');
    var userid = <?=$userid?>;  //此处为取得上方php值
    btn.onclick = function () {
        if (userid > 0){
            window.location.href='index.php?g=Member&m=Tousu&a=index';
        }else {
            alert('请先登陆');
        }
    }
</script>