Jquery- fetch checkbox selected values and save it to cookies at modal close button click

Spent almost two days trying to figure out this problem. I have modal popup with dynamic checbox list (generated from database) and close button on modal popup. What I want is that when user click 'Close' button, then modal popup is closed but the same time I want to get all selected checboxes values to save in string.

<asp:Button ID="btnHide" runat="server" Text="Close" OnClick="btnHide_Click" OnClientClick="HideModalPopup()"/>

protected void btnHide_Click(object sender, EventArgs e)
        {
           string names=checkCheckboxes(); //calling WORKING function which reutrns all selected checboxes from modal popup in a string, splited by comma
           Response.Write(names); //trying to write 'names' variabile which contains all selected checboxes on screen
        }

jQuery function:

function HideModalPopup() {
    $find("mpe").hide();
    return false;
}

Problem is that when I click close button, modal popup disapeared, but no values are saved to variabile 'names' in btnHide_Click method. How can I get selected checkboxes from modal popup to this function? What is wrong with this code?

Please help me out.

Solution

You can do it via ajax call. In your clientside function where you hide modal box before that fetch all the checkbox checked value using .each() jquery n then call ajax request and save it to ur database.

function HideModalPopup() { 
     var fetchAllChkbox= $("input[name=chkboxName]:ch ecked").map( function () {return this.value;}).get().join(",");

         $find("mpe").hide(); 
        // $.ajax  call to save to database etc
        return false;
     }

Note- herechkboxName is name of chkboxss,

Updated Answer : Get all selected checkbox values in a variable and create cookie session and set selected value to it.

JQuery:

$(document).ready(function () {
   $("#clkme").click(function () {
        var getValue = ""; // get vall checkbox selected values
        $("[id*=CheckBoxList1] input:checked").each(function () {
        var Value = $(this).val();
        getValue += Value + ",";
        });
       $.cookie('your_cookie_name', getValue); // set cookies
       alert($.cookie('your_cookie_name')); // read cookies and alert it
    });
  });

HTml markup:

<asp:CheckBoxList ID="CheckBoxList1" runat="server">
</asp:CheckBoxList>
  <div id="clkme">CLICK ME</div>

Note: just import this cookie.js https://github.com/carhartl/jquery-cookie