How to Update Parent Window after close child window

Parent Page Code:-
<a href="javascript:openDialog('IRClearanceActivation.aspx?empcode=<%# Eval("ADEMPCODE") %>&ResigID=<%# Eval("RESIGNATIONID") %>',800,480)">
<img id="Img2" style="padding-right: 2px; vertical-align: middle" src="../../Images/icon_ticketbullet.gif" runat="server" alt="Ticket" />
<b>ACTIVATE</b></a>
    <script type="text/javascript">
    function openPopupwithScrol(strOpenUrl, width, height) {
            var winTop = (screen.height - height) / 2;
            var winLeft = (screen.width - width) / 2;
            var windowFeatures = "location=no,status=no,width=" + width + ",height=" + height;
            windowFeatures = windowFeatures + ",left = " + winLeft + ",";
            windowFeatures = windowFeatures + "top=" + winTop + ",resizable" + ",scrollbars";
            //window.open (strOpenUrl, "mywindow", "TOOLBAR=no,MENUBAR=no,SCROLLBARS=yes,RESIZABLE=no,LOCATION=no,DIRECTORIES=no,STATUS=no,width="+width+",height="+height);
            window.open(strOpenUrl, "mywindow", windowFeatures);
        }
        function openDialog(strOpenUrl, width, height) {
             var retVal = window.showModalDialog(strOpenUrl, null, "dialogHeight:" + height + "px;dialogWidth:" + width + "px;status:0;resizable:1;edge:raised;scroll:1");
            if (retVal == "1") {
                window.location = "ListPendingClearance.aspx";
                }
        }
    </script>

Child Window Code:-
 BTN Click:- ScriptManager.RegisterClientScriptBlock(Page, GetType(), "al1", "alertMe('1')", true);
 <script language="javascript" type="text/javascript">
   function alertMe(val)
   {   
        if(val=="1")
        {
            alert("Information updated successfully");
            window.returnValue ="1";
            window.close();
        }
        else if(val=="2")
        {
            alert("Update failed");
            window.returnValue ="1";
            window.close();
        }
   }
   </script>