scrollbar width

scroobar-width.js

var scrollBarWidth = (function(){
    var html = document.documentElement;
    var outer = document.createElement("div");
    var inner = document.createElement("div");
    
    outer.style.visibility = "hidden";
    outer.style.width = "100px";
    outer.style.overflow = "scroll";
    
    outer.appendChild(inner);
    html.appendChild(outer);
    
    var outerWidth = outer.offsetWidth;
    var innerWidth = inner.offsetWidth;
    
    html.removeChild(outer);
    
    return outerWidth - innerWidth;
})();