DistinguishedFieldAttribute – Assembly ref missing error

Hi,

I have created a c# class lib which has the attribute [DistinguishedFieldAttribute]. I have added

using Microsoft.XLANGs.BaseTypes;

I beleive I miss some assembly reference. Can any one help me out.

[Err]

The type or namespace name ‘XLANGs’ does not exist in the namespace ‘Microsoft’ (are you missing an assembly reference?)

The type or namespace name ‘DistinguishedFieldAttribute’ could not be found (are you missing a using directive or an assembly reference?)

[/Err]