Incorporating JavaScript in HTML – Web Applications Stack Exchange

I am new in HTML writing via dreamweaver 2020.

I have added the following codes to dw:-

<head>
        <meta charset="utf-8">
        <title>The ul, ol, and li tags</title>
        <style type="text/css"> body {background-color: #E4E978;}</style>
        <script type = "text/javascript">;
            today = new Date();
            dateValue = today.getYear() + "午" + today.getMonth() + "月" + today.getDay() + "日";
            window.alert("n welcome nn today is " + dateValue "nn redirecting to my site");
            var hour, min;
            function showclock();
                {   now = new Date();
                    hour = now.getHours();
                    if (hour <=9) hour = "0" + hour;
                    min = now.getMinutes();
                    if (min <= 9) min = "0" + min;
                    document.clock.time.value "NOW is" + hour + "/" + min;
                    setTimeout("showclock()", 1000 );
                }
        </script>
    </head 

I found that they were totally ignored.

Other things that I have tried (and with the same being-ignored result) are:-

(1) Use instead;

(2) adding <!– in case some browsers have no JavaScript interpretation power;

(3) running on different engines (edge etc.)

Please let me know what procedures that I have missed.