w3schools javascript button code example

Example 1: HTML button onclick

<!DOCTYPE html>
<html>
  <head>
    <title>Title of the document</title>
  </head>
  <body>
    <p>There is a hidden message for you. Click to see it.</p>
    <button onclick="myFunction()">Click me!</button>
    <p id="demo"></p>
    <script>
      function myFunction() {
        document.getElementById("demo").innerHTML = "Hello Dear Visitor!</br> We are happy that you've chosen our website to learn programming languages. We're sure you'll become one of the best programmers in your country. Good luck to you!";
      }
    </script>
  </body>
</html>

Example 2: onclick in js

<input type="text" name="text" id="test" onmouseover="skriv('klick')">
    <input type="button" name="send" value="Skicka" id="klick" onclick="skriv('test')">
    
    
    <script src="lib/script.js"></script>


// in lib/script.js

  function skriv(name) {
    document.getElementById(name).style.backgroundColor='red';
  }