function getScrollY() {
  var scrOfY = 0;
  if( typeof( window.pageYOffset ) == 'number' ) {
    //Netscape compliant
    scrOfY = window.pageYOffset;
  } else if( document.body && ( document.body.scrollLeft || document.body.scrollTop ) ) {
    //DOM compliant
    scrOfY = document.body.scrollTop;
  } else if( document.documentElement && ( document.documentElement.scrollLeft || document.documentElement.scrollTop ) ) {
    //IE6 standards compliant mode
    scrOfY = document.documentElement.scrollTop;
  }
  return scrOfY ;
}

function findObjYPos(obj) {
	var curtop = 0;
	
	if (obj.offsetParent) {
	 do { curtop += obj.offsetTop;}
	 while (obj = obj.offsetParent);
	}
			
	return curtop;
}

window.onscroll = function() {

 if (BrowserDetect.browser != "Explorer") {
  var contentNav = document.getElementById('content-nav');
  var content = document.getElementById('content');
  var windowTop = getScrollY();
  var contentTop = findObjYPos(content);
  
  if (windowTop > contentTop) {
	 contentNav.className = 'fixed-nav';
	 content.style.paddingTop = contentNav.offsetHeight + 'px';
  } else {
   contentNav.className = 'rounded-top';
	 content.style.paddingTop = contentNav.offsetHeight & 'px';
  }
 }
}