Order of bootstrap horizontal form elements mixed up?

Question

I'm trying to create a horizontal form layout with bootstrap: two dropdowns and an input box. I've succeeded in getting the elements horizontal using the .form.inline class, but since I added this class, for some reason my input box has jumped to the left of the two dropdowns, even though it follows the dropdowns in the html. I need it to be to the right of the dropdowns--any solutions? Here's the code:

<form class=".form-inline" role="form">

        <!-- Department button -->
        <div class="btn-group">
        <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
            Department <span class="caret"></span>
        </button>
        <ul class="dropdown-menu" role="menu">
            <li><a href="#">Action</a></li>
            <li><a href="#">Another action</a></li>
            <li><a href="#">Something else here</a></li>
            <li class="divider"></li>
            <li><a href="#">Separated link</a></li>
        </ul>
        </div>


        <!-- Course button -->

        <div class="btn-group">
        <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown">
            Course Number <span class="caret"></span>
        </button>
        <ul class="dropdown-menu" role="menu">
            <li><a href="#">Action</a></li>
            <li><a href="#">Another action</a></li>
            <li><a href="#">Something else here</a></li>
            <li class="divider"></li>
            <li><a href="#">Separated link</a></li>
        </ul>
        </div>


        <!--Professor Input-->
            <div class="col-sm-4">
            <input type="text" class="form-control" id="input" placeholder="Instructor">
            </div>

    </form>

Answer 1

<form class=".form-inline" role="form">

Notice that you have class=".form-inline" as the class when it should be class="form-inline" without the period.

You also need to change the input parent div's class from .col-sm-4 to form-group