C#: Make and use DLL

//MAKING DLL

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MakeMyDLL
{
    public class graphics //REMEMBER THIS CLASS NAME
    {
        public string Makemydll()
        {
            return ("made my dll");

        }
    }
}

//USING DLL
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using MakeMyDLL;


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



        private void btnDraw_Click(object sender, EventArgs e)
        {
            MakeMyDLL.graphics ob = new MakeMyDLL.graphics();
            string ans = ob.Makemydll();
            MessageBox.Show(ans);
        }





        private void btnDraw_MouseHover_1(object sender, EventArgs e)
        {
            label1.Text = "hey";
        }



    }
}