how to add select statement in aspx.cs

protected void Button1_Click(object sender, EventArgs e)
    {
        using (SqlCommand cmd = new SqlCommand("Insert into Emplo ([Name],[Password],[Designation],[Dept],[D O B],[Sex],[Address]) values (@Name,@pass,@des,@dept,@DOB,@Sex,@Address)", con))
        {
            cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = TextBox1.Text;
            cmd.Parameters.Add("@des", SqlDbType.VarChar).Value = TextBox2.Text;
            cmd.Parameters.Add("@dept", SqlDbType.VarChar).Value = TextBox3.Text;
            cmd.Parameters.Add("@DOB", SqlDbType.SmallDateTime).Value = TextBox4.Text;
            cmd.Parameters.Add("@Sex", SqlDbType.VarChar).Value = RadioButton1.SelectedItem.Text;
            cmd.Parameters.Add("@Address", SqlDbType.VarChar).Value = TextBox5.Text;
            string sa = CreateRandomPassword(6);
            cmd.Parameters.Add("@pass", SqlDbType.VarChar).Value = sa;
            con.Open();
            cmd.ExecuteNonQuery();
            Response.Write("<script>alert('Registered successfully......!')</script>");
            Response.Write("<script>alert('Password is  " + Server.HtmlEncode(sa.ToString()) + "')</script>");
   
//i want a select stmt here to select the last row value from db so that i can increment the retrieved value and insert into the current row using this format String.Format("a{0:0000}", i); 
        }
        con.Close();
    }