Change font to Comic Sans if reader is using Adblock (and display a message at the top)

gistfile1.txt

<script type="text/javascript">
	var iframe = document.createElement("iframe");
    iframe.height = "1px";
    iframe.width = "1px";
    iframe.id = "ads-text-iframe";
    iframe.src = "/adframe.js";
    document.body.appendChild(iframe);

    var a = [
			"In a world free from ads, one font reigns supreme. COMIC SANS!",
	 		"Today's ad free site is brought to you by Comic Sans.",
		    "Please enjoy our website free from ads, showcased in regal Comic Sans.",
		    "Achievement Unlocked! You've unlocked AdBlocker. Your reward is Comic Sans.",
		    "Hello Adblock User! You have unlocked a secret font! Unfortunately, it’s Comic Sans.",
		    "Hello Adblock User! You have won 1 free font! Unfortunately, it’s Comic Sans.",
		    "Some things are even worse than ads. Meet Comic Sans.",
		    "One of our fonts got loose and we can't find it. Do you see Comic Sans anywhere?"
    ];
    var amsg = a[Math.floor(Math.random() * a.length)];

    setTimeout(function(){
       var iframe = document.getElementById("ads-text-iframe");
       if(iframe.style.display == "none" || iframe.style.display == "hidden" || iframe.style.visibility == "hidden" || iframe.offsetHeight == 0) {
            $( "body" ).prepend( '<div style="display:block;padding:4px;background:gold">' + amsg + '</div>' );
            $('*').css("font-family","Comic Sans MS");
            iframe.remove();
       }else{
            iframe.remove();
       }
    }, 500);
</script>

This requires jQuery to work. And you should probably stick it in the footer.

Strange combination of vanilla JS and jQuery; why not just make those two jQuery functions use plain JS instead and remove the dependency?