How do we find the width of scroll bar?

Question

Do you know any cross-browser methods?

Answer 1

There aren't any way working cross browser (IE is the problem, as always), sorry

Answer 2

window.scrollBarWidth = function() { 
  document.body.style.overflow = 'hidden';  
  var width = document.body.clientWidth; 
  document.body.style.overflow = 'scroll';  
  width -= document.body.clientWidth;  
  if(!width) width = document.body.offsetWidth - document.body.clientWidth; 
  document.body.style.overflow = '';  
  return width;  
}