I have two ordered lists and user can move items between them. I am using jQuery UI's Selectable for both of them. Problem is that when I move item from the middle of the list it leaves an empty space behind. How can I make list shrink according to the how many items is actually in the list?

HTML

<ol id="allUnits">
    <li class="ui-state-default">Item 1</li>
    <li class="ui-state-default">Item 2</li>
    <li class="ui-state-default">Item 3</li>
    <li class="ui-state-default">Item 4</li>
    <li class="ui-state-default">Item 5</li>
</ol>

<input id="arrowRight" type="image" alt="Move item to right" src="<%= Url.Content("~/Content/Images/arrowRight.png")%>" />
<input id="arrowLeft" type="image" alt="Move item to left" src="<%= Url.Content("~/Content/Images/arrowLeft.png")%>" />

<ol id="productUnits">
    <li class="ui-state-default">Item 1</li>
    <li class="ui-state-default">Item 2</li>
    <li class="ui-state-default">Item 3</li>
    <li class="ui-state-default">Item 4</li>
    <li class="ui-state-default">Item 5</li>
</ol>

jQuery

$().ready(function () {
    $("#allUnits").selectable();
    $("#productUnits").selectable();

    $('#arrowRight').click(function () {
        return !$('#allUnits .ui-selected').remove().appendTo('#productUnits').removeClass(".ui-selected");
    });
    $('#arrowLeft').click(function () {
        return !$('#productUnits .ui-selected').remove().appendTo('#allUnits').removeClass(".ui-selected");
    });
});