How to modify this registration box?

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
<script type="text/javascript">
var startat=5;
function disableRegBtn(bdisable){
        document.getElementById("regBtn").disabled=bdisable;
}
 
function showTime(){
    if(startat==0){
        clearInterval(timeId);
        document.getElementById("p1").innerHTML="";
        disableRegBtn(true);
        return;
        }
    document.getElementById("p1").innerHTML=startat + "";
    startat--;      
}
window.onload=function(){
    document.getElementById("taid").readOnly=true;
    disableRegBtn(true);
    timeId=setInterval("showTime()",1000);
}
</script>
<textarea id="taid" cols="30" rows="5">:
1.
2.
3.
</textarea> <p id="p1"><input id="regBtn" type="button" value="" />

</body>
</html>

countdown, after 5 4 3 2 1, it shows "can register now"

but 

<input id="regBtn" type="button" value="" />

cannot be displayed. The disableRegBtn (true);
in the
showTime function cannot be written as
disableRegBtn (fasle);
disableRegBtn ("disabled");

Html javascript
Oct.16,2021

you directly change the content of the p tag and overwrite the input tag inside. It is recommended to change it this way.
and there is a mistake in canceling the assignment of disabled. It should be false. 

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title></title>
</head>

<body>
    <script type="text/javascript">
        var startat = 5;

        function disableRegBtn(bdisable) {
            document.getElementById('regBtn').disabled = bdisable;
        }

        function showTime() {
            if (startat == 0) {
                clearInterval(timeId);
                document.getElementById("tip").innerHTML = "";
                disableRegBtn(false);
                return;
            }
            document.getElementById("tip").innerHTML = startat + "";
            startat--;
        }
        window.onload = function () {
            document.getElementById('taid').readOnly = true;
            disableRegBtn(true);
            timeId = setInterval("showTime()", 1000);
        }
    </script>
    <textarea id="taid" cols="30" rows="5">:
        1.
        2.
        3.
    </textarea>
    <p id="p1">
        <div id="tip"></div>
        <input id="regBtn" type="button" value="" />
    

</body>

</html>

is very simple, because your code document.getElementById ("p1"). InnerHTML= "can now register" ; simply replace all the elements in your p tag, and naturally your buttons will be gone.
solution:

  1. write the button separately from the p tag, so that when you insert content directly into the dom node, your button will not be replaced.
    2. Instead of using the attribute innerHTML ,
  2. inserts a new dom node
    3. into the p tag instead.

above.

Previous: What kind of encryption is used by default or base64 is used by Ant Design of React to upload files on Upload?

Next: How to do the ranking of 1 million users?

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3a998-e777.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3a998-e777.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?