Some Weak Auras help

[Deleted]

Hello everyone,

My problem in tl;dr terms: I am trying to setup weakauras addon for something very specific and I fail mizerably every time.
The setup I want: basically I only need some sort of button to flash when Evocation has 30 sec left of CD. That's all.
Anyone here has the knowledge on how to set that thing up? (a string will be much appreciated)

Cheers,
Natha29

Edit: I tried for the past hour to search on internet for something similar, nothing worked

[BreaKerNZ]

http://pastebin.com/cpW7fEUd makes a noise when Evo is 15 seconds off cooldown