[exec]

document.onclick = function (e) {
	e = e || window.event;
	elem = e.target || e.srcElement;
	switch (elem.id) {
	case 'bbutton_1':
		var a = 'a1';
		break;
	case 'bbutton_2':
		var a = 'a2';
		break;
	default:
		var a = 0;
	}
}