Incrementing the counter variable and storing it in the database in ASP.Net

hello sir i m having 4 radio buttons on default2.aspx page

on the same page i m using a database

it's columns are uname and status

whenever the user clicks on the radiobutton the status of that name should increment by 1(counter variable).

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;

public partial class Default2 : System.Web.UI.Page
{
    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
    int c = 0;
    int d = 0;
    int k = 0;
    int f = 0;
    protected void Page_Load(object sender, EventArgs e)
    {
        con.Open();
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        if (RadioButton1.Text == "Krishna")
        {
            //Label1.Text=RadioButton1.Text;
            c++;
            SqlCommand cmd = new SqlCommand("update detail set status='"+c.ToString()+"' where uname='"+"Krishna"+"'",con);
            cmd.ExecuteNonQuery();
            con.Close();
            
        }

        else if (RadioButton1.Text == "Amit")
        {
            //Label1.Text = RadioButton1.Text;
            d++;
            SqlCommand cmd = new SqlCommand("update detail set status='" + d.ToString() + "' where uname='" + "Amit" + "'", con);
            cmd.ExecuteNonQuery();
            con.Close();
        }

        else if (RadioButton1.Text == "Deelip")
        {
            //Label1.Text = RadioButton1.Text;
            k++;
            SqlCommand cmd = new SqlCommand("update detail set status='" + k.ToString() + "' where uname='" + "Deelip" + "'", con);
            cmd.ExecuteNonQuery();
            con.Close();
        }

        else
            
            {
                //Label1.Text = RadioButton1.Text;
                f++;
                SqlCommand cmd = new SqlCommand("update detail set status='" + f.ToString() + "' where uname='" + "Yash" + "'", con);
                cmd.ExecuteNonQuery();
                con.Close();
            }
    }
}