A jQuery select box replacement library (live demo)

$('.your-select').fSelect();

$('.your-select').fSelect({
 placeholder: 'Select some options',
 numDisplayed: 3,
 overflowText: '{n} selected',
 noResultsText: 'No results found',
 searchText: 'Search',
 showSearch: true
});

• placeholder (str) - the default placeholder text
• numDisplayed (int) - the number of values to show before switching to the overflowText
• overflowText (str) - the text to show after exceeding the numDisplayed limit
• noResultsText (str) - the text to show if no choices exist (or an empty string)
• searchText (str) - the search box placeholder text
• showSearch (bool) - show the search box?

$('.your-select').fSelect('reload');
$('.your-select').fSelect('destroy');

Add the multiple attribute to your <select> to enable multi-select:

<select class="your-select-box" multiple="multiple">