Get the width / height of the browsers scroll bar

getScrollWidth.js

function getScrollWidth(){
    // Create a div
    var scrollEle = document.createElement("div"),
        scrollWidth = 0;

    // Set it's styling
    scrollEle.style.width = "100px";
    scrollEle.style.height = "100px";
    scrollEle.style.overflow = "scroll";
    scrollEle.style.position = "absolute";
    scrollEle.style.top = "-9999px";

    // Append element to the page body
    document.body.appendChild(scrollEle);
    
    // Get the width
    scrollWidth = scrollEle.offsetWidth - scrollEle.clientWidth;
    
    // Remove the Element 
    document.body.removeChild(scrollEle);
    
    return scrollWidth;
}

document.write(getScrollWidth());