onclick in js

document.getElementById("myBtn").addEventListener("click", function() {
  alert("Hello World!");
});<button onclick="myFunction()">Click me</button>

<p id="demo"></p>

<script>
function myFunction() {
  document.getElementById("demo").innerHTML = "Hello World";
}
</script>document.getElementById('button').onclick = function() {
   alert("button was clicked");
};var button = document.querySelector('button');
button.onclick = function() {
  //do stuff
}<button onclick="Function()">Text</button>	<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';
  }