Copiar Campos com mesmo ID

by Rapha Souza

HTML

<script src="//code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<link rel="stylesheet" href="//stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css">
<script src="//cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.0/umd/popper.min.js"></script>
<script src="//stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
<html>
<head>
	<title></title>
<script type="text/javascript">
function copy_form()
{
	id('nome_copy').value = id('nome').value;
	id('idade_copy').value = id('idade').value;
}
function id( el ){
	return document.getElementById( el );
}
window.onload = function()
{
	id('copiar').onclick = function()
	{
		copy_form();
	}
}
</script>
</head>
<body>
	Form Original:
	<form action="" method="post">
		<input type="text" name="nome" id="nome" value="Bruno Rocha" />
		<input type="text" name="idade" id="idade" value="21 anos" />
	</form>
	
	Form Copia:
	<form action="" method="post">
		<input type="text" name="nome" id="nome_copy" />
		<input type="text" name="idade" id="idade_copy" />
	</form>
	
	<input type="button" name="copiar" id="copiar" value="copiar" />
</body>
</html>

CSS

.row {
  background: #f8f9fa;
  margin-top: 20px;
}

.col {
  border: solid 1px #6c757d;
  padding: 10px;
}