<!DOCTYPE html>
<html>
    <head>
        <script>
            let stream = null;

            function promptForAudioAndVideo()
            {
                navigator.mediaDevices.getUserMedia({ audio: true, video: true }).then((s) => {
                    stream = s;
                    console.log("Got user media");
                }).catch((error) => console.log(`Failed with error: ${error}`));
            }

            function promptForAudioOnly()
            {
                navigator.mediaDevices.getUserMedia({ audio: true, video: false }).then((s) => {
                    stream = s;
                    console.log("Got user media");
                }).catch((error) => console.log(`Failed with error: ${error}`));
            }

            function haveStream()
            {
                return stream !== null;
            }
        </script>
    <head>

    <body onload="promptForAudioAndVideo()">
    </body>
</html>