Hi Petroclus;
In order to do a IN clause in the EF first release you will need to download the LinqKit which is free to use which will build a predicate so that it can be used in the query.
Download LinqKit from here at the bottom of page ==>
http://www.albahari.com/nutshell/linqkit.aspxUnzip the file and open the solution in Visual Studio and set the Solution to Release.
Compile the solution. If no errors close the solution.
Now in your current project add a reference to the LinqKit.dll which will be in the bin/release directory of LinqKit project.
Add the using statement to your project ==> using LinqKit;
The below function and query should work not.
The following link is info on LinqKet.
Dynamically Composing Expression Predicates
http://www.albahari.com/nutshell/predicatebuilder.aspxFernando