I\'ve created this fiddle, it allows the user to click on either art or video, dynamically populating the the second listbox with the list associated with those selections. Ther
Have a look at this solution:- Using the data attribute to keep track of the items parent list selector and avoiding a loop with the help of this selector and data attribute.
http://jsfiddle.net/pramodsankar007/rMpBv/
$('#add').click(function () {
var itemsToAdd = [];
$("#SelectBox2 option:selected").each(function () {
var optionVal = $(this).val();
var key = $(this).data('key');
if($('#SelectedItems option[value="' + optionVal + '"][data-key="' + key +'"]').length == 0)
{
itemsToAdd.push($(this).removeAttr('selected').clone(true));
}
});
$("#SelectedItems").append(itemsToAdd);
});
});