Get Scrollbar Width

getScrollbarWidth.js

function getScrollbarWidth () { 
  var inner = document.createElement('p'); 
  inner.style.width = "100%"; 
  inner.style.height = "200px"; 
  var outer = document.createElement('div'); 
  outer.style.position = "absolute"; 
  outer.style.top = "0px"; 
  outer.style.left = "0px"; 
  outer.style.visibility = "hidden"; 
  outer.style.width = "200px"; 
  outer.style.height = "150px"; 
  outer.style.overflow = "hidden"; 
  outer.appendChild(inner); 
  document.body.appendChild(outer); 
  var w1 = inner.offsetWidth; 
  outer.style.overflow = 'scroll'; 
  var w2 = inner.offsetWidth; 
  if (w1 == w2) w2 = outer.clientWidth; 
  document.body.removeChild(outer); 
  return (w1 - w2); 
}; 

getScrollbarWidth.min.js

function getScrollbarWidth(){var a=document.createElement("p");a.style.width="100%",a.style.height="200px";var b=document.createElement("div");b.style.position="absolute",b.style.top="0px",b.style.left="0px",b.style.visibility="hidden",b.style.width="200px",b.style.height="150px",b.style.overflow="hidden",b.appendChild(a),document.body.appendChild(b);var c=a.offsetWidth;b.style.overflow="scroll";var d=a.offsetWidth;return c==d&&(d=b.clientWidth),document.body.removeChild(b),c-d}