Como obter as listas de IDs de elemento <li> na JQuery-UI classificável
Gostaria de obter todos os IDs de elementos 'li', como a, b, c, ... g.
Como obter todas as listas de IDs de elementos 'li'?
Obrigado!
Exemplo classificável de JQuery-UI
<!doctype html>
<html lang="en">
<head>
<script>
$( function() {
$( "#sortable" ).sortable();
$( "#sortable" ).disableSelection();
} );
</script>
</head>
<body>
<ul id="sortable">
<li id="a" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 1</li>
<li id="b" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 2</li>
<li id="c" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 3</li>
<li id="d" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 4</li>
<li id="e" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 5</li>
<li id="f" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 6</li>
<li id="g" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>Item 7</li>
</ul>
</body>
</html>