radiobutton checkbutton

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private string Ctype;
        private string Cartype;
        private void tip_Click(object sender, EventArgs e)
        {
            info.Text="username:"+a.Text+","+"user type:"+Ctype+","+"car type:"+Cartype;
        }

        private void school_CheckedChanged(object sender, EventArgs e)
        {
            Ctype = "school";
        }

        private void company_CheckedChanged(object sender, EventArgs e)
        {
            Ctype = "company";
        }

        private void car_CheckedChanged(object sender, EventArgs e)
        {
            if (car.Checked)
            {
                Cartype = Cartype + car.Text;
            }
            else
            {
                Cartype.Replace(car.Text+"</br>","");
                Cartype.Trim();
            }
        }

        private void suv_CheckedChanged(object sender, EventArgs e)
        {
            if (suv.Checked)
            {
                Cartype = Cartype + suv.Text;
            }
            else
            {
                Cartype.Replace(suv.Text + "</br>", "");
                Cartype.Trim();
            }
        }

        private void mpv_CheckedChanged(object sender, EventArgs e)
        {
            if (mpv.Checked)
            {
                Cartype = Cartype + mpv.Text;
            }
            else
            {
                Cartype.Replace(mpv.Text + "</br>", "");
                Cartype.Trim();
            }
        }

        private void clear_Click(object sender, EventArgs e)
        {
            Cartype = "";
        }

        


       

       
    }
}

radiobutton checkbutton