[ksa]

$('input[name=options]:checked', '#form').val();

Как вариант...

<form id='form'>
	<input type='checkbox' name='options' value='test' checked />
</form>
<script type='text/javascript'>
var o=document.querySelector('#form input[name=options]:checked');
var val=(o)? o.value: '';
alert(val)
</script>