<!doctype html> <html> <head> </head> <body> <form> <input type="button" value="Button1" onclick="btnClick(event)"> <input id="b2" type="button" value="Button2"> </form> </body> </html>
function btnClick(event) {
alert(event.target.value+"클릭됨!!");
}
document.getElementById('b2').onclick = function(event) {alert(event.target.value+"클릭됨!!")}