Removing elements from an array

I need to remove elements from an array .

The elements to be removed are the elements that are duplicated on a database.

So i will check the duplicated ids and need to remove then fromthe array

And i will be processing the rest of the array in other function.

thanks in advance

[man]array_unique[/man]
[man]unset[/man]

how can i unset a variable wich was affected by array_unique
(eliminate the duplication and the array position that was duplicated)