</button>
          </div>
        </div>
      </div>

      <div class="control-group">
        <label for="single" class="control-label">Select2 single select sizes</label>
        <div class="controls">
          <select id="span_small" class="select2 input-small">
            <option></option>
            <option value="A">A</option>
            <option value="B">B</option>
            <option value="C">C</option>
          </select>
          <select id="span_medium" class="select2 input-medium">
    