jquery - How do I populate values for multiple chosen plugin? -

i using jquery plugin (http://harvesthq.github.io/chosen/) , having trouble populating selected values textbox.

based on options page, says $('.my_select_box').trigger('chosen:updated');

however have multiple select boxes, say

<select id="select1" class="chzn-select" name="select1" data-placeholder="choose employee..." multiple="true" style="width: 350px; display: none;"></select>  <select id="select2" class="chzn-select" name="select2" data-placeholder="choose employee..." multiple="true" style="width: 350px; display: none;"></select>  <select id="select3" class="chzn-select" name="select3" data-placeholder="choose employee..." multiple="true" style="width: 350px; display: none;"></select> 

and in jquery script have

$('.chzn-select', this).chosen(); // use prepopulate? 

but if had selected values 3 select boxes, how populate values again?

i have function saves them database though:

$("#btnsave").click(function(){      var firstval= $("#select1").val();     var secondval= $("#select2").val();     var thirdval = $("#select3").val();       $.ajax({         type: "post",         url: "mypost",         data: {             firstval:firstval,             secondval :secondval,             thirdval :thirdval;         },         ....// do here?       });   }); 

help appreciated. thanks!

desired output when page loaded:

i think need add selected attribute in option tag, see example here

in html:

<select id="ddlcarlist" multiple="multiple">     <option value="volvo">volvo</option>     <option value="saab">saab</option>     <option value="mercedes" selected="selected">mercedes</option>     <option value="audi" selected="selected">audi</option> </select> 

in javascript:

<script> jquery(document).ready(function() {    jquery("#ddlcarlist").chosen(); }); </script> 

check demo here