How to get checkbox value in multiselect onchange event

Question

I implement jquery multiselect and its working properly now i need to add extra feature that when a user select another option in dropdown ( check another checkbox ) then i want to get the value of the related option

in above picture in did not insert checkbox it is automatically inserted by jquery now i want that if i select the check =box with XYZ then i want to get the value of XYZ which is the id of XYZ

here is how i implemented it

 <select multiple="multiple" id="CParent" name="parent" class="box2 required">
                        @foreach (var item in Model.Categories.OrderBy(c => c.Name))
                        {

                            if (Model.Coupon.Categoryid.Id == item.Id)
                            {   
                            <option  selected="selected" value="@item.Id">@item.Name</option>

                            }
                            else
                            {
                            <option  value="@item.Id">@item.Name</option>                                                                                  
                            }
                        }
                    </select>

and it is how it looks like after rendering in browser source

Thanks in advance for helping me .

what i tried yet

  $('#CParent input:checked').change(function () {

        var parentid = $(this).val()+'';
        var array = parentid.split(",");
        alert(array);
        getchildcat(array[array.length -1]);
    });

});

Edit

Code to initialize multiselect

$("#CParent").multiselect({
    header: "Choose only THREE items!",
    click: function () {
        if ($(this).multiselect("widget").find("input:checked").length > 3) {
            $(warning).show();
            warning.addClass("error").removeClass("success").html("You can only check three checkboxes!");
            return false;
        }
        else if ($(this).multiselect("widget").find("input:checked").length <= 3) {

            if ($(warning).is(":visible")) {

                $(warning).hide();
            }

        }

    }
});

Answer 1

try this

$('#CParent').val();

this will give you the selectbox value

OR

from docs

 var array_of_checked_values = $("#CParent").multiselect("getChecked").map(function(){
   return this.value;   
 }).get();