ad component gui texture

hey guys I'm looking for a script which ads an var based gui texture as an component to a game object when clicked on that game object...

my scripting sculls are very low so pls don't make proposals i don't understad :)

my idea by now was something like first i have a var for the picture or texture i won't to show via gui

then there is a on mouse Down function and it should ad(or activate(true/false) )a gui component with the texture i mentiont with the var.

thx for your help