JQuery UI selectmenu not displaying correctly

I am attempting to use the JQuery selectmenu widget with my select elements. However, they are not displayed correctly. It seems that the divs that get wrapped around the select by the selectmenu widget are not being put in the right place. These divs should appear in the section I have highlighted, wrapped around the select elements. They are instead appearing several lines below this, where I have outlined in red. Does anyone know why this is happening, or what I am doing wrong?

Here is the html code:

<div id="tabs-1">
    <div id = 'hide'><input type='hidden' id='modelid'>
        <label for='model'>Model</label><br>
        <input id='model' type='text' name='model' tabindex=2 />
        <input type='hidden' id='input'><br>
        <label for='man'>Manufacturer</label><br>
        <select id='man' name='manufacturerid' tabindex=3>
            <option value='' selected > Select Manufacturer</option>
            <?php
                $sql = "SELECT manufacturerid,`code`,`name` AS manufacturer 
                FROM manufacturer ORDER BY manufacturer;";
                $manufacturerResult = mysql_query($sql);
                while ($record = mysql_fetch_array($manufacturerResult)) {
                    echo "<option value='".$record['manufacturerid']."'>".$record['manufacturer']."</option>";
                }   
            ?>
        </select><br>
        <label for='itemtype'>Inventory Type</label><br>
        <select id='itemtype' name='inventorytypeid' tabindex=4>
            <option value='' selected > Select Part Type</option>
            <?php
                $sql = "SELECT inventorytypeid,`name` AS inventorytype 
                FROM inventorytype WHERE active = 'True' ORDER BY inventorytype;";
                $inventorytypeResult = mysql_query($sql);
                while ($record = mysql_fetch_array($inventorytypeResult)) {
                    echo "<option value='".$record['inventorytypeid']."'>".$record['inventorytype']."</option>";
                }
            ?>
        </select><br>
        <input id='active' type='checkbox' name='activate' tabindex=5 />
        <label for='active'>Active</label>
    </div>
</div>

And here is the javascript:

$("#tabs").tabs();
$( "#search, #update, #add, #back" ).button();
$('select').selectmenu();

I would also like to add that the tabs and buttons display correctly; the only thing not working is the selectmenu.

And finally, here is the image: