Example HTML:
//jQuery extension method:_x000D_
jQuery.fn.filterByText = function(textbox) {_x000D_
return this.each(function() {_x000D_
var select = this;_x000D_
var options = [];_x000D_
$(select).find('option').each(function() {_x000D_
options.push({_x000D_
value: $(this).val(),_x000D_
text: $(this).text()_x000D_
});_x000D_
});_x000D_
$(select).data('options', options);_x000D_
_x000D_
$(textbox).bind('change keyup', function() {_x000D_
var options = $(select).empty().data('options');_x000D_
var search = $.trim($(this).val());_x000D_
var regex = new RegExp(search, "gi");_x000D_
_x000D_
$.each(options, function(i) {_x000D_
var option = options[i];_x000D_
if (option.text.match(regex) !== null) {_x000D_
$(select).append(_x000D_
$('<option>').text(option.text).val(option.value)_x000D_
);_x000D_
}_x000D_
});_x000D_
});_x000D_
});_x000D_
};_x000D_
_x000D_
// You could use it like this:_x000D_
_x000D_
$(function() {_x000D_
$('select').filterByText($('input'));_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<select>_x000D_
<option value="hello">hello</option>_x000D_
<option value="world">world</option>_x000D_
<option value="lorem">lorem</option>_x000D_
<option value="ipsum">ipsum</option>_x000D_
<option value="lorem ipsum">lorem ipsum</option>_x000D_
</select>_x000D_
<input type="text">
_x000D_
Live demo here: http://www.lessanvaezi.com/filter-select-list-options/