Error: (perhaps you forgot to load "Module Name")?

Hello,

I created a custom perl module called SelectAffiliate.pm which I added
to the /rt2/lib/RT folder with the others.

I then created code to use the module, which I put in
/rt2/WebRT/html/Elements

Now when this code is executed I get the following error:

begin error
error: Can’t locate object method “new” via package
“RT::SelectAffiliate” (perhaps you forgot to load
“RT::SelectAffiliate”?) at
/usr/local/rt2/WebRT/html/Elements/SelectAffiliate line 29, line 29.

context: …
25: %}
26:
27:
28: <%INIT>
29: my $sa=new RT::SelectAffiliate ($session{‘CurrentUser’});
30: $sa->UnLimit;
31: </%INIT>
32:
33: <%ARGS>

code stack:
/usr/local/rt2/WebRT/html/Elements/SelectAffiliate:29
/usr/local/rt2/WebRT/html/Search/PickRestriction:18
/usr/local/rt2/WebRT/html/Search/Listing.html:106
/usr/local/rt2/WebRT/html/autohandler:60
end error

Do I somehow have to load the module in my environment before I can use
it?

Any help / direction is greatly appreciated.

Alan