Client side scripts for showing or hiding "Show a link to add new entries"

Client side scripts for showing or hiding "Show a link to add new entries"

It will be nice to have ability to hide or show " Show a link to add new entries in
by deluge script on client side. 

It can be usefull for managing permissions for adding new values  to form,  
f rom other forms with lookup fields

Like this: field1:ui.showAddLink() or  field1:ui.hideAddLink()