Habilitar/desabilitar botão por checkbox

Usado em sites com politicas ou contrato

by Jairo Fontes

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<script src="https://code.jquery.com/jquery-1.12.0.min.js"></script>
<div class="col-md-6">
  <!-- termos -->
  <div class="checkbox">
    <label>
      <input type="checkbox" class="checkContrato"> Eu li e concordo com o <a href="#">Contrato de Serviços</a>
    </label>
  </div>
</div>
        
<div class="col-md-9 marginTopG">
  <div class="form-group">
    <label class="col-md-4 col-md-push-3 text-left">*Campos obrigatórios</label>
    <div class="col-md-3 col-md-push-3">
      <button name="enviar" class="btnEnviar btn btn-raised btn-success btn-block">Enviar</button>
      <span class="feedback"></span>
    </div>
  </div>
</div>

JavaScript

$('.btnEnviar').attr('disabled','disabled');
$('.checkContrato').change(function(){
  if($(this).is(":checked")){
    $('.btnEnviar').removeAttr('disabled');
  }else{
    $('.btnEnviar').attr('disabled','disabled');
  }
});