摘自javascript基础教程
开始：
1.将脚本放在哪里：
1.1 放在html和<html>之间
范例：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript</title>
<script type="text/javascript">
window.onload = writeMassage;
function writeMassage() {
document.getElementById("helloMessage").innerHTML = "hello world";
}
</script>
</head>
<body>
<h1 id="helloMessage">
</h1>
</body>
</html>
1.2 放在标签之间
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript</title>
</head>
<body>
<h1 id="helloMessage">
<script>
document.getElementById("helloMessage").innerHTML = "hello world";
</script>
</h1>
</body>
</html>
1.3 使用外部脚本
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>javascript</title>
<script src="script01.js"></script>
</head>
<body>
<h1 id="helloMessage">
</h1>
</body>
</html>
script.01.js写脚本
根据自己的需要选择