Required Field Validator based on condition

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Required_Field_Validator_based._Default" %>





   


   

   

   
           
               
           
           
               
               
               
           
           
               
               
               
           
           
           
               
               
               
                
           
           
           
           
           
               
           
           
           
           
               
           
           
               
           
       

Registration Form
Name:
Email
Role	AutoPostBack="True" onselectedindexchanged="rbtRole_SelectedIndexChanged">                         Administrator                         Shop floor User                          Key User                          Others
onclick="btn_register_Click" />

   

   

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;
using System.Data.SqlClient;
namespace Required_Field_Validator_based
{
    public partial class _Default : System.Web.UI.Page
    {
        string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        SqlCommand com;


        protected void btn_register_Click(object sender, EventArgs e)
        {
            if (rbtRole.Text == "Others")
            {
                SqlConnection con = new SqlConnection(strConnString);
                com = new SqlCommand();
                com.Connection = con;
                com.CommandType = CommandType.Text;
                com.CommandText = "insert into login values(@Name,@Email,@role)";
                com.Parameters.Clear();
                com.Parameters.AddWithValue("@Name", txtName.Text);
                com.Parameters.AddWithValue("@Email", txtEmail.Text);
                com.Parameters.AddWithValue("@role", TextBox1.Text);
                if (con.State == ConnectionState.Closed)
                    con.Open();
                com.ExecuteNonQuery();
                con.Close();
                lblmsg.Text = "Data entered successfully!!!";
                clear();
            }
            else
            {
                SqlConnection con = new SqlConnection(strConnString);
                com = new SqlCommand();
                com.Connection = con;
                com.CommandType = CommandType.Text;
                com.CommandText = "insert into login values(@Name,@Email,@role)";
                com.Parameters.Clear();
                com.Parameters.AddWithValue("@Name", txtName.Text);
                com.Parameters.AddWithValue("@Email", txtEmail.Text);
                com.Parameters.AddWithValue("@role", rbtRole.SelectedValue);
                if (con.State == ConnectionState.Closed)
                    con.Open();
                com.ExecuteNonQuery();
                con.Close();
                lblmsg.Text = "Data entered successfully!!!";
                clear();
            }
          
        }

        protected void rbtRole_SelectedIndexChanged(object sender, EventArgs e)
        {
            lblmsg.Text = "";

            if (rbtRole.SelectedValue == "Others")
            {
                panell.Visible = true;
                TextBox1.CausesValidation = true;
            }
            else
            {
                panell.Visible = false;
                TextBox1.CausesValidation = false;
            }
        }
        void clear()
        {
            TextBox1.Text = "";
            txtEmail.Text = "";
            txtName.Text = "";
            rbtRole.ClearSelection();
        }
    }
}

I don't know how you design your form but if you are not showing any thing on Administrator or the remaining expect others I would recommend you to design as follows