Question: I am currently going through a tutorial using Visual Studio 11 beta. When trying to set the max length of a field value in one of my classes:

```
[MaxLength(50)]
public string LastName { get; set; }

```

It errors out and wont let me compile because the `MaxLength()` function exists in two places:

> 
> Error 4 The type '**System.ComponentModel.DataAnnotations**.MaxLengthAttribute' exists in both 'c:\Users\me\Documents\Visual Studio 11\ContosoUniversity\packages\EntityFramework.4.1.10331.0\lib\net40\EntityFramework.dll' and 'c:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.5\System.ComponentModel.DataAnnotations.dll'
> 
> 
> 

I have tried to remove both files but that just causes more issues because other code in my project is dependent upon them.

Is there a way I can tell it to use one or the other?

**All of these approaches don't seem to be working for me.. Refer to the comments under the answers.. Any other ideas?**

Thanks

Answer: 
Use using at the top of your code:

```
using MaxLength = System.ComponentModel.DataAnnotations

```
Try using extern alias <http://msdn.microsoft.com/en-us/library/ms173212.aspx> to differentiate between the two assemblies

Also check out <http://bartdesmet.net/blogs/bart/archive/2006/10/07/4502.aspx> near the bottom of the page is an example