Hi Shivaraj,
Try this...
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Save_multiple_select_item_dropdown.WebForm1" %>
<!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>Untitled Page</title>
<script language="javascript" type="text/javascript">
function window.confirm(str)
{
execScript('n = msgbox("'+str+'","4132")', "vbscript");
return(n == 6);
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Button ID="btnOk" runat="server" OnClientClick="javascript:return confirm('Are you sure to proceed?');" OnClick="btnOk_Click" Text="OK" />
</div>
</form>
</body>
</html>
using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
namespace Save_multiple_select_item_dropdown
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void btnOk_Click(object sender, EventArgs e)
{
}
}
}
Thanks