if (typeof(readingBG) === "undefined") {var readingBG = "#f6f6f6";}
function toggleReadingMode(buttonElement) {
var contentStyle = document.getElementById("content").style;
if (contentStyle.backgroundColor == readingBG) {
contentStyle.backgroundColor = "";
buttonElement.alt= "Reading Mode";
buttonElement.title= "Change to Reading Mode";
} else {
contentStyle.backgroundColor = readingBG;
readingBG = contentStyle.backgroundColor; //handle IE color format change
buttonElement.alt = "Normal Mode";
buttonElement.title= "Change to Normal Mode";
}
}
$(document).ready(function() {
var rb=document.createElement("input");
rb.type="image";
rb.src="https://upload.wikimedia.org/wikipedia/commons/thumb/8/85/Eye_Icon.svg/20px-Eye_Icon.svg.png";
rb.alt="Reading Mode";
rb.title="Change to Reading Mode";
rb.setAttribute( "onClick", "toggleReadingMode(this)" );
var h=document.getElementById('firstHeading');
h.insertBefore(rb,h.firstChild);
});