[rt-users] Creating new CF type

[GAksenov at imbank.ru]

Hi!
Can somebody point me - how to create new CF type, like "Select multiple 
values"? 
I have RT 3.4.2 on redhat FC3 and i'm trying to create new CF type for 
storing URL (in the name i plan to have Name and in the description the 
URL for this name).
I create new type in CutomField_Overlay.pm

%FieldTypes = (
    Urlcf => [
        'Select multiple URLs', # loc
        'Select one URL',               # loc
        'Select up to [_1] URLs',       # loc
    ],
....

and create two new Elements:
EditCustomFieldUrlcf and ShowCustomFieldUrlcf (just like a copy from 
EditCustomFieldSelect and ShowCustomFileldSelect) 
but it dosn't help :(
Can ypu point me right way to define new CF type
Thanks a lot.

with best wishes
 German Aksenov