document.write("<h1>Hello, World</h1>");

console.log("hello, world!!!");

function message() {
    alert("Alert Message!!");
}

// 이거 잘 기억하기.
function test() {
     document.getElementById('demo').innerHTML="message";
}
window.onload = test;

new Date();

document.write(Date()+"<br>");
var cur_time = new Date();
document.write(cur_time);