isclicked in javascript code example

Example 1: how to check if the button is clicked or not in javascript

if(document.getElementbyId("id do item").clicked == true){
	window.alert("ok")   
}

Example 2: javascript click event

<button onclick="myFunction()">Click me</button>

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

<script>
function myFunction() {
  document.getElementById("demo").innerHTML = "Hello World";
}
</script>