Asp.net Membership security and sql server permissions and roles

Hi, the asp.net membership system use folder based system for the application security ,
here my scenario ;
a simple example
in a page i have three buttons
addinvoice/delete invoice/modifyInvoice
the user may have only the addinvoice permission so i cannt figure out how to do this in asp.net membership system
creating a page for every permissions combination is not a very good option

for example, in an old delphi/firebird application i have written  

the administrator of the application can create other users, and give them CRUD rights on each table plus other rights, these rights are translated into grant/revoke instructions and sent to the firebird server

my question is : how this security mechanism interact on the sql server permissions/roles level :
now, is th ...