Messsage doesn't show

I need to show a message whenever user Select option"A"
heres the code for aspx

Code:

---

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="~/Search.aspx.cs" Inherits="HITS.Search" MasterPageFile="~/hits_main.master"%>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
    <asp:ScriptManager ID="scMgr" runat="server"/>
<div>
<%--<asp:UpdatePanel ID="UP1" runat="server" >
  <ContentTemplate>
  </ContentTemplate>
 
</asp:UpdatePanel> --%>
    <table  cellspacing="10" border=".02"> 
    <tr> 
      <td  align="left"  >
          <asp:RadioButtonList ID="RBl1" runat="server" AutoPostBack="True"                             
                                CellPadding="2" CellSpacing="5"
              onselectedindexchanged="RBl1_SelectedIndexChanged">
            <asp:ListItem  Value="G" Selected="True" >Regular Grants</asp:ListItem>
            <asp:ListItem Value ="A">ARRA Grants</asp:ListItem>
            <asp:ListItem Value ="C">Contract</asp:ListItem>
            </asp:RadioButtonList>               
       
        </td>

---

If you mean by showing a message that you want to alert an message (javascript alert function), you can do this as next (inside your selectedIndexChanged eventhandler)

Code:

---

// if the dropdownlist is on a normal page
Page.ClientScript.RegisterClientScriptBlock(Page.GetType(), "message_script", "alert('You selected option A');", true);

//if the page is on an UpdatePanel
ScriptManager.RegisterClientScriptBlock(Page, Page.GetType(), "message_script", "alert('You selected option A');", true);

---

Thanks it work really nicely
I am happy.