[jQuery] use of jquery to change existing code

[Snowman]

Hello,

I am trying to add an effect to my existing JS.  Not an expert with JS
by any means, I can manage to work my way around is most instances.  I
have jquery library called in my code because of a password strength
meter so I might as well try and utilize it's functions.

My code:
if(value=="UK"){
document.getElementById('vat').style.display='block';}

This is changing a div id=vat with style=display:none to
display:block; as you can see.  I'd like that to fade in.  Checked out
Cody's examples but can't figure out how to impliment.  Can anyone
help?

Thanks