var date = new Date();
var year = date.getFullYear();//如何写好JavaScript?
var month = date.getMonth() + 1;
var day = date.getDate();
if (month < 10) {
month = "0" + month;
}
if (day < 10) {
day = "0" + day;
}
var datetime = year + "-" + month + "-" + day;
window.onload=datetime;
var div = document.createElement("div");
div.innerHTML= datetime;
document.body.appendChild(div);