<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>p0c</title>
</head>
<body>
</body>
<form>
<input id="test" type="text" name="username" value="test"/><br />
<input type="text" name="password" /><br />
<input type="submit" name="submit" value="submit" onclick="form()"/>
<input type="reset" name="reset" value="reset" />
</form>
<script>
function form(){
var get = document.getElementById("test").value;
document.write(get);
}
</script>
</html>
输入内容后点击"submit"，没有打印username的值，求解答
