Using Geteffectiverightsfromacl from asp.net

[Nissim Levi]

Hi.
I'm trying to use GetEeffectiveRrightsFromAcl api to show a web client only
the folder that
he have at least read permission and the function return access denied
(error 5).
when I'm using the same code from windows app the code work perfect.
can I use the function GetEeffectiveRrightsFromAcl from asp.net or there
is an alternative
way to do the same.

Thanks in advance.
Nissim L