JAVASCRIPT

Select multiple

<script type="text/javascript">
    $(document).ready(function() {
        $('#example-post').multiselect({
            includeSelectAllOption: true,
            enableFiltering: true
        });
    });
</script>
<form class="form-horizontal" method="POST" action="post.php">
    <div class="form-group">
        <label class="col-sm-2 control-label">Multiselect</label>
        <div class="col-sm-10">
            <select id="example-post" name="multiselect[]" multiple="multiple">
                <option value="1">Option 1</option>
                <option value="2">Option 2</option>
                <option value="3">Option 3</option>
                <option value="4">Option 4</option>
                <option value="5">Option 5</option>
                <option value="6">Option 6</option>
            </select>
        </div>
    </div>
    <div class="form-group">
        <label class="col-sm-2 control-label">Text Input</label>
        <div class="col-sm-10">
            <input type="text" name="text" class="form-control" placeholder="Text Input" />
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <div class="checkbox">
                <label>
                    <input type="checkbox" name="checkbox"> Checkbox
                </label>
            </div>
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <div class="radio">
                <label>
                    <input type="radio" name="radio"> Radio 1
                </label>
            </div>
            <div class="radio">
                <label>
                    <input type="radio" name="radio"> Radio 2
                </label>
            </div>
        </div>
    </div>
    <div class="form-group">
        <div class="col-sm-offset-2 col-sm-10">
            <button type="submit" class="btn btn-default">Submit</button>
        </div>
    </div>
</form>

html select multiple

$(".chosen-select").chosen({
  no_results_text: "Oops, nothing found!"
})

select2 multiple selected values

in_array($value, $array)