var buttons = document.querySelectorAll('.btn-click-me');
for (var i = 0; i < buttons.length; i++) {
var self = buttons[i];
self.addEventListener('click', function (event) {
// prevent browser's default action
event.preventDefault();
// call your awesome function here
MyAwesomeFunction(this); // 'this' refers to the current button on for loop
}, false);
}