Basic Example Event JS (mouseover)
by JuanMa Garrido
HTML
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<a href="#" id="my_link" class="btn btn-default">No one's around</a>
CSS
#my_link { margin:30px; text-align:center; font-size:30px !important ; width:500px; }
JavaScript
var link = document.getElementById("my_link");
var input = document.getElementById("my_input");
link.addEventListener("mouseover", function() {
this.innerHTML = "Feeling a presence..."
});
link.addEventListener("mouseout", function() {
this.innerHTML = "Click Me!"
});