Hi
If we have to do this task on client side without using postback then we can do using Javascript like this
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title><script type="text/javascript">
function HidDiv()
{
document.getElementById(‘Div1’).style.display = "none";
document.getElementById(‘Div2’).style.display = "none";
}function showhidesearch()
{
var radio1=document.getElementById(‘<%=RadioButtonList1.ClientID %>’);var rblopts = radio1.getElementsByTagName("input");
if(rblopts[0].checked)
{
document.getElementById(‘Div1’).style.display="block";
document.getElementById(‘Div2’).style.display="none";
}
else if(rblopts[1].checked)
{
document.getElementById(‘Div2’).style.display="block";
document.getElementById(‘Div1’).style.display="none";}
}</script>
</head>
<body onload = "javascript:HidDiv();">
<form id="form1" runat="server">
<div style="margin-left:200px;"><asp:RadioButtonList ID="RadioButtonList1" runat="server"
RepeatDirection="Horizontal" style="font-weight: 700"
onclick="showhidesearch()" >
<asp:ListItem Value="1">First Div</asp:ListItem>
<asp:ListItem Value="2">Second Div</asp:ListItem>
</asp:RadioButtonList>
<br /><div id="Div1" style="background-color:Blue; width:200px; height:200px;" runat="server">
<br />
<b> This is the first div </b></div>
<br />
<br /><div id="Div2" style="background-color:Lime; width:200px; height:200px;" runat="server">
<br />
<b> This is the Second div</b></div>
</div>
</form>
</body>
</html>
Chandradev's Blog 
Excellent post. I certainly appreciate this site.
Continue the good work!
Thanks. I will do it.
I’m amazed, I must say. Rarely do I encounter a blog that’s both equally educative
and interesting, and let me tell you, you have hit
the nail on the head. The problem is something which too few people are speaking intelligently about.
I am very happy that I found this during my hunt
for something relating to this.