You can try out the following code segment,
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
</head>
<body>
<input id ="btn" type="button" value="click" onclick="event1(), event2()"/>
</body>
</html>
<script type="text/javascript">
function event1() {
//defination of the event-1
}
function event2() {
//defination of the event-2
}
</script>