Untitled

<!DOCTYPE html>
<html lang="es-MX">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Módulo de Ventas</title>

<!-- CSS -->
<link href="css/bootstrap.css" rel="stylesheet">`introducir el código aquí`
<link href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet">
<style>

        body{
            background-color: cadetblue;
        }

    </style>
</head>
<body>


<div class="container">
<br>
<header>
        <nav class="navbar-default navbar-fixed-top navbar-inverse">
            <div class="container-fluid">
            <div class="navbar-header">
                <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar-1">
                    <span class="sr-only">Menu</span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>
                    <span class="icon-bar"></span>

                </button>
                <a href="#" class="navbar-brand">Logo-Play 4 Fun</a>
            </div>

                <div class="collapse navbar-collapse" id="navbar-1">
                    <ul class="nav navbar-nav">
                        <li><a class="" href="">Producto</a></li>
                        <li><a href="">Compra</a></li>
                        <li><a href="active">Venta</a></li>
                    </ul>
                </div>
            </div>
        </nav>
    </header>
</div>
<br>
<br>
<br>
<br>

<h2 class="text-center">Módulo de Ventas</h2>
<div class="container">
    <div class="row">
        <div class="col-sm-12 col-s-4">
    <select class="custom-select" id="cmbClientes">
  <option selected>Clientes Existentes de la Base de Datos</option>
  <option value="1">Cliente Uno</option>
  <option value="2">Cliente Dos</option>
  <option value="3">Cliente Tres</option>
    </select>
    <select class="custom-select" id="cmbEmpleados">
  <option selected>Empleados Existentes de la Base de Datos</option>
  <option value="1">Empleado Uno</option>
  <option value="2">Empleado Dos</option>
  <option value="3">Empleado Tres</option>
    </select>
    <select class="custom-select" id="cmbProductos">
  <option selected>Productos Existenes de la Base de Datos</option>
  <option value="1">Producto Uno</option>
  <option value="2">Producto Dos</option>
  <option value="3">Producto Tres</option>
    </select>
    </div>
    </div>
</div>

<br>
<br>
<br>
<br>
<br>
<br>
<br>
<!-- JS -->
<script src="js/jquery-1.11.3.min.js"></script>
<script src="js/bootstrap.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/js/bootstrap.min.js"></script>
</body>
</html>