Toggling MC alpha with a button

Hey all, I’m trying to have one button turn an mc’s alpha from 0 to 100, then next press from 100 to 0 but since I am new to action scripting, I am kinda just hit and miss with things.

I have this part done…

on (press) {
if (“mc-instructions”,_alpha, “0”) {
setProperty(“mc-instructions”, _alpha, “100”);

Which obviously makes the alpho 0 mc appear, but when it comes to the same button going away, I am at a loss. I would assume some sort of ‘if’ statement, but, as an actionscript hack… I am not all that familiar with them.