HTML for bootstrap inline forms - see it in action here: http://adsynth-alerts.herokuapp.com/alerts/new

gistfile1.html

          <!-- This goes in the form -->
          <div class="control-group conditions">
          </div>
          <button type="button" class="btn btn-small add-condition">+</button>
                  
          <!-- This is the html for the individual line items, to be rendered by your favorite engine -->
        <div class="alert-inline alert-condition form-inline" style="margin-bottom:10px;">
            <input name="condition_subject" placeholder="Subject" required="true">

            <select name="condition_operator">
            <option value="=">is
            <option value="!=">is not
            <option value="contains">contains
            <option value="starts">starts
            </select>

            <input name="condition_value" placeholder="Value" required="true">

            <button type="button" class="btn btn-danger btn-small remove-condition">X</button>
        </div>