Using JavaScript simple alert box :
Page.RegisterClientScriptBlock("", "<script>alert('Book Added');</script>");
Response.Write("<script>alert('Book Added')</script>");
Or you can display your own window by
using the modalpopupExtender:
CSS Effect
----------
<style type="text/css">
.modalBackground
{
background-color: #CCCCFF;
filter: alpha(opacity=40);
opacity: 0.5;
}
.ModalWindow
{
border: solid1px#c0c0c0;
background-color: #99ccff;
padding: 0px10px10px10px;
position: absolute;
top: -1000px;
}
</style>
ModapPopUp Code
------------------------
<cc1:ModalPopupExtender TargetControlID="Button2" BackgroundCssClass="modalBackground"
CancelControlID="btnMsg" PopupControlID="Panel1" PopupDragHandleControlID="btnMsg"
ID="ModalPopupExtender2" runat="server">
</cc1:ModalPopupExtender>
<asp:Panel ID="Panel1" runat="server" CssClass="ModalWindow">
<%--Button popup--%>
<center>
<table runat="server">
<tr>
<td bgcolor="#cccccc" style="border: 1px; border-color: Black;" height="20px" align="left"
valign="top">
<div style="border-bottom-width: 1px; border: 1px solid">
Deletion</div>
</td>
</tr>
<tr>
<td align="center" bgcolor="#99ccff">
<br />
The Record has been deleted!
</td>
</tr>
</table>
<asp:Button ID="btnMsg" runat="server" Text="OK" /><br />
</center>
</asp:Panel>
<asp:Button ID="Button2" runat="server" Text="OK" /><br />