onlcik and event handler javascript w3schools code example

Example 1: button click function in js

<script>
  $(document).ready(function(){
    $('#MyButton').click(function(){
       CapacityChart();
    });
  });
</script>

<input type="button" value="Capacity Chart" id="MyButton" >

Example 2: calling function on click html

<img src="hospital.png" id="hospitals" onclick="damarkers();">