quedaria asi?? es correcto?
Código:
<!DOCTYPE HTML>
<html lang="en-US">
<head>
<meta charset="UTF-8">
<title></title>
<link rel="stylesheet" href="" />
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
</head>
<body>
<select id = "foo">
<option value = "1">Primer formulario</option>
<option value = "2">Segundo formulario</option>
</select>
<div class="container">
<div id="formularios" class="row">
<form id="cotizacion" action="">
<div class="col-md-4">
<input class="form-control input-lg" type="text" placeholder="cotizacion d1">
<input class="form-control" type="text" placeholder="cotizacion d2">
<input class="form-control input-sm" type="text" placeholder="cotizacion d3">
</div>
</form>
<form action="" id="emision">
<div class="col-md-4">
<input class="form-control input-lg" type="text" placeholder="emision d1">
<input class="form-control" type="text" placeholder="emision d2">
<input class="form-control input-sm" type="text" placeholder="emision d3">
<button id="enviar" type="submit" class="btn btn-default">Enviar</button>
</div>
<div class="col-md-4">
</div>
</form>
</div>
</div>
<script type="text/javascript">
document.querySelector("enviar").addEventListener("click", function(){
if (document.querySelector("#formularios").value == 1){
document.querySelector("#cotizacion").submit();
}
else{
document.querySelector("#emision").submit();
}
}, false);
</script>
</body>
</html>