add an eventlistener to a button code example
Example 1: javascript onclick event listener
document.getElementById("myBtn").addEventListener("click", function() {
alert("Hello World!");
});
Example 2: javascript pass parameter to event listener
var someEventHander=function(){
console.log(event,param1,param2);
}
//add listener
document.getElementById("someid").addEventListener('click',someEventHander.bind(event,param1,param2));