filter a select box with jQuery

Question

I tried to made text input that filtering selectbox. I'm trying to fix it alot of time but it still not working well. Maybe because it is in hebrew?

HTML:

<option value="628077"> new york</option>
<option value="244228">רמת גן<option>
<option value="641332"> דימונה</option>
<option value="240812"> הזורעים</option>
.
.
.
<option value="640375"> עתניאל</option>
<option value="344580">  חיפה</option>
<option value="440560">  בית רבן</option>
<option value="520098"> הרצליה</option>
</select>

jQuery:

<script type="text/javascript" >
        $('#city').keyup(function () {

            var valthis = $(this).val();
            var num = 0;
            $('select#DropDownList1>option').each(function () {
                var text = $(this).text();
                if(text.indexOf(valthis) != -1)  
               { $(this).show();} 
               else{ $(this).hide();}

            });

        });
</script>

I need your help!

Answer 1

$('#city').keyup(function () {
    var valthis = $(this).val().toLowerCase();

    $('select#DropDownList1>option').each(function () {
        var text = $(this).text().toLowerCase();
        if (text.indexOf(valthis) !== -1) {
            $(this).show(); $(this).prop('selected',true);
        }
        else {
            $(this).hide();
        }
    });
});

DEMO Hope it helps.