data not loading in gridview from radiobutton : i have a code that i intend to use the radio button to retrieve data from a table and load it on a grid view.but once i click on the radio button , no data is loaded in the grid view.below is my code.`enter code here`  protected void Radiobuttonlist1_CheckedChange(Object sender, EventArgs e)
    {
        string Value = Radiobuttonlist1.SelectedItem.Value.ToString();
       
        if (Value == "Patients")
        {
            string connect = TraceBizCommon.Configuration.ConfigSettings.ConnectionString;
            SqlConnection conn = new SqlConnection(connect);

            conn.Open();
            SqlCommand cmd = new SqlCommand("select PatientName,PatientCellPhone from CustomerInformation", conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            conn.Close();
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }
        else if(Value== "Suppliers")
        {
            string connect = TraceBizCommon.Configuration.ConfigSettings.ConnectionString;
            SqlConnection conn = new SqlConnection(connect);

            conn.Open();
            SqlCommand cmd = new SqlCommand("select VendorName,VendorPhone from VendorInformation", conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            conn.Close();
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }
        else if ( Value== "Employees")
        {
            string connect = TraceBizCommon.Configuration.ConfigSettings.ConnectionString;
            SqlConnection conn = new SqlConnection(connect);
            conn.Open();
            SqlCommand cmd = new SqlCommand("select EmployeeName,EmployeeMobilePhone from PayrollEmployees", conn);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            conn.Close();
            GridView1.DataSource = ds;
            GridView1.DataBind();
        }

    }`