A Multiple Selection DropDownList (a CheckBoxList Inside a DropDownList)

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

namespace TestMultiCheck
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            ArrayList array = new ArrayList();
            for (int i = 0; i < 100; i++) array.Add(i.ToString());
            MultiCheckCombo1.AddItems(array);
        }

        protected void LinkButton1_Click(object sender, EventArgs e)
        {
            Label1.Text = MultiCheckCombo1.Text;

            //keep this line. It copies the values you checked to the control again.
            //Otherwise, it will be blank.
            MultiCheckCombo1.Text = Label1.Text; 
        }
    }
}