window.onload = function(){
document.getElementById("calcButton").onclick = function(){
var Y = parseInt(document.getElementById("year").value);
var M = parseInt(document.getElementById("month").value);
var D = parseInt(document.getElementById("date").value);
var g = ((((Y - 2009) % 19) * 11 + M + D) +1);
if (M < 3) g = g + 2;
g = g % 30;
document.getElementById("result").innerHTML = "月齢："+g;
}
}