function filterData() {

    var data = { col: $('#filterPopup').attr('name'), val: $('#filterPopupInput').val() };

    __doPostBack('filterColumn', JSON.stringify(data));

}

if (IsPostBack) {

    if (Request.Params["__EVENTTARGET"] != null && Request.Params["__EVENTTARGET"] == "filterColumn")

    {

        string data = Request["__EVENTARGUMENT"];

        JavaScriptSerializer jss = new JavaScriptSerializer();

        var d = jss.Deserialize<dynamic>(data) as Dictionary<string, object>;

        string filterColumn = d["col"].ToString();

        string filgterValue = d["val"].ToString();

    }

}