how to add css animation to an element of the skin

[Fgorge]

Hello,
In an HTML web page I wrote this little script and CSS to animate a <div> using CSS animation :

Code: Select all

function play_FG(whichElement) {
	element= document.getElementById(whichElement);
	element.classList.add("animation_FG");
    element.style.animationPlayState = "running";
}

function pause_FG(whichElement) {
	element= document.getElementById(whichElement);
	element.classList.remove("animation_FG");

}

CSS :

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.animation_FG {
 animation-name: fade_anim_FG;
  animation-duration: 1s;
  animation-play-state: paused;
  animation-iteration-count: infinite;
  }

@keyframes fade_anim_FG {
  50% {opacity: 40%;}
}

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<button onmouseover="play_FG('targetRed')" onmouseleave="pause_FG('targetRed')" >Play Red</button>

Everything work fine in a simple HTML page with a div with an ID named targetRed.

But inside my skin, when I try to modify an element ID = targetRed using a simple javascript :

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javascript:
play_FG('targetRed');

I've got this error
.

error js.jpg (94.63 KiB) Viewed 23809 times

Any help will be very appreciated.
F.