How to create a custom property in CMS 5

After som searching i found this EPiServer forum thread that show how to create a custom property in CMS 5. Not rocket sience, but I like to have one place to find code samples that will speed up my work. With this new blog I have just such a place

using System;
using System.Collections.Generic;
using System.Text;
using EPiServer;
using EPiServer.Core;
using EPiServer.DataAbstraction;
using EPiServer.PlugIn;
using EPiServer.Web.PropertyControls;
using System.Web.UI.WebControls;namespace EPiServerDemo.PropertyTypes
{
  /// <summary>
  /// Custom PropertyData implementation
  /// </summary>
  [Serializable]
  [PageDefinitionTypePlugIn(DisplayName="My demo dropdown")]
  public class MyDropDownCore : EPiServer.Core.PropertyString
  {
  public override IPropertyControl CreatePropertyControl()
  {
  return new MyDropDownPropType();
  }
  }
public class MyDropDownPropType : EPiServer.Web.PropertyControls.PropertySelectControlBase
  {
  protected override void SetupEditControls()
  {
  base.SetupEditControls();DropDownList inputControl = this.EditControl;
  inputControl.Items.Add("Red");
  inputControl.Items.Add("Blue");
  inputControl.Items.Add("Green");

inputControl.SelectedValue = this.PropertyData.Value as string;
  }
  }
}

Getting your applications configuration

In .Net 3.0 you use the ConfigurationManager class, found in the System.Configuration namespace, to get a hold of your applications configuration. You need to make a reference to the System.Configuration.dll

To get your AppSettings, use the following line of code:

string MyString = System.Configuration.ConfigurationManager.AppSettings["keyname"].ToString();

To get you connection strings, use:

string connString = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;

and add one node in web.config:

<connectionStrings>
<add name="connstr" connectionString=""/>
</connectionStrings>