AJAX pop up question for ASP.NEt project

Question

Hello,

I have 2 pages. One of them shows Location Info and the other shows Company Info. If the user changes Location Info in page 1 and hits "Save" the page should throw a popup asking user if he wants to update company info as well. If he clicks yes, it has to update in both Company table and Location info. and if he hits No, it has to save just in the location table in db.

This is the popup code.

<table id="pnlPopupMerchantUpdate" runat="server" style="display:none">
<tr>
    <td>
        <asp:Panel runat="server" CssClass="modalPopup">
            <table width="350" height="80" class="warningPopup">
                <tr>
                    <td>
                        <!-- <img src="images/warning_blue.gif" alt="Warning" /> -->
                    </td>
                    <td colspan="2" align="left" style="padding-left: 75px; padding-top: 10px;">
                        Do you wish to update the Location Information as well.
                    </td>
                </tr>
                <tr>
                    <td align="center" colspan="4">
                        <input id="btnYesMerchant" type="button" value="Yes" class="popupButton" /> 
                        <input id="btnNoMerchant" type="button" value="No" class="popupButton" />                           
                    </tr>
            </table>
        </asp:Panel>
    </td>
</tr>

protected void btnSave_Click(object sender, ImageClickEventArgs e) { SaveData();

}

With this code, No will just close the popup and yes will update only Location table. How to get the desired result? What should be changed here or anything to be added in the code behind!!

Thanks all!