关于html的问题，iframe设置高度无效，如何解决？

在PHP中，iframe里height参数无效
代码


<!DOCTYPE html>
<html lang="en">
  <head>
      <script></script>
      <button onclick="ok()" >*</button>
    <meta charset="UTF-8" />
    <title>*</title>
<script>
function getQueryString(name) {
    var result = window.location.search.match(new RegExp("[\?\&]" + name + "=([^\&]+)", "i"));
    if (result == null || result.length < 1) {
        return "";
    }
    return result[1];
}
var xuehao=getQueryString("xuehao"))
</script>



<script>


var a = new Date();
var time1 =  a.getTime()

function po(){
    var b = new Date();
    var time2 =  b.getTime();   
    var time = time2 - time1;
    var url = '*‘;
    window.location.href = url;
}

</script>
  </head>
  <body>
 <iframe   width="100%"      height='100%' frameborder='0' align='center' allowfullscreen='true'    allow="autoplay"   id='iframe'   src="*"  ></iframe>

  </body>
</html>

关于html的问题