Hello. I want to create a like button like on facebook. So far I have a link table with userid and ideaid. This has a unique index with userid and ideaid. Thus if you try and like something twice you cant as you get an error message. However I don't want that error message, I just want the button to disappear if the like button is pressed by a logged in user. But I'm stuck. Any ideas?
In the screen preparation, use an aggregate to find all records with the UserId and IdeaId values.  Then, put the Like button in an If block and use the aggregate Count value to determine if the button should show by setting the If block to Count > 0.

Hope this helps,
Hi Eddy S, Create a boolean parameter and set it to the dispaly property of like button then in Preparation use a query having  Unique index in where clause, if count of query is >0 then assign the boolean value false else true.
Don't forget to refresh the like button in the end of the like button action.