<div class="container">
    <div class="row">
        <div class="col-md-6 col-md-offset-3">
            <form action="submit" class="form-horizontal">
                <legend>Personal information:</legend>
                <div class="form-group">
                    <label class="col-sm-4 control-label">First Name</label>
                    <div class="col-sm-8">
                        <input type="text" name="firstname" class="form-control" placeholder="Mickey">
                    </div>
                </div>

                <div class="form-group">
                    <label class="col-sm-4 control-label">Last Name</label>
                    <div class="col-sm-8">
                        <input type="text" name="lastname" class="form-control" placeholder="Mouse">
                    </div>
                </div>

                <div class="form-group">
                    <label class="col-sm-4 control-label">Birth date</label>
                    <div class="col-sm-8">
                        <input type="text" name="birthdate" class="form-control">
                    </div>
                </div>

                <div class="form-group">
                    <div class="col-sm-offset-4 col-sm-8">
                      <input type="submit" value="Submit" class="btn btn-default">
                    </div>
                </div>

            </form>
        </div>
    </div>
  </div>