<!DOCTYPE html>
<html>
<head>
<style>
progress { -webkit-appearance: none; border: 2px solid red; }
progress:indeterminate { border: 2px solid blue; }
</style>
<script>
window.onload = function() {
    document.getElementById("dymanicindeterminate").removeAttribute("value");
    document.getElementById("dymanicdeterminate").setAttribute("value", 0.5);
}
</script>
</head>
<body>
<progress id="indeterminate"></progress>
<br>
<progress id="dymanicindeterminate" value=0.5></progress>
<br>
<progress id="dymanicdeterminate"></progress>
</body>
</html>