Web forms EF4 CodeFirst CTP5 KeyAttribute not found
I'm using code-first in Web Forms (not MVC) with EF4 and CTP5, and when trying to decorate a property with the [Key] attribute, it doesn't show up in the intellisense and get compilation error saying KeyAttribute was not found. Here is my code:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.ComponentModel.DataAnnotations;
    
    namespace ERP.Models
    {
    	public class CustomerAddress
    	{
    		[Key]
    		public int AddressID { get; set; }
    		public int CustomerID { get; set; }
    		public string Address1 { get; set; }
    		public string Address2 { get; set; }
    		public int CityID { get; set; }
    		public int SateID { get; set; }
    	}
    }

I have included the DataAnnotations library, all looks ok, but the [Key] attribute is not found. Any hint is highly appreciated. Thanks!
Web forms EF4 CodeFirst CTP5 KeyAttribute not found
===

I'm using code-first in Web Forms (not MVC) with EF4 and CTP5, and when trying to decorate a property with the [Key] attribute, it doesn't show up in the intellisense and get compilation error saying KeyAttribute was not found. Here is my code:

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.ComponentModel.DataAnnotations;
    
    namespace ERP.Models
    {
    	public class CustomerAddress
    	{
    		[Key]
    		public int AddressID { get; set; }
    		public int CustomerID { get; set; }
    		public string Address1 { get; set; }
    		public string Address2 { get; set; }
    		public int CityID { get; set; }
    		public int SateID { get; set; }
    	}
    }

I have included the DataAnnotations library, all looks ok, but the [Key] attribute is not found. Any hint is highly appreciated. Thanks!