var isNav = navigator.appName == "Netscape";

function popup(url)
{
	var xPos, yPos;
	var height = "280";
	var width = "445";
	
	if(isNav)
	{
		xPos = window.screenX + 60;
		yPos = window.screenY + 140;
	}
	else
	{	
		xPos = window.screenLeft + 60;
		yPos = window.screenTop;
	}

	popupSizePos(url, xPos, yPos, height, width);
}

function popupSize(url, height, width)
{
	var xPos, yPos;
	
	if(isNav)
	{
		xPos = window.screenX + 60;
		yPos = window.screenY + 140;
	}
	else
	{	
		xPos = window.screenLeft + 60;
		yPos = window.screenTop;
	}

	popupSizePos(url, xPos, yPos, height, width);
}

function popupSizePos(url, xPos, yPos, height, width)
{
	window.open(url, "termsandconditions", "toolbar=no,directories=no,alwaysRaised=yes,dependent=yes,location=no,menubar=no,resizable=no,scrollbars=yes,screenX="+xPos+",screenY="+yPos+",height="+height+",width="+width+",left="+xPos+",top="+yPos);
}

function popupNormal(url)
{
	var xPos = 50;
	var yPos = 50;
	var height = screen.availHeight - yPos - 200;
	var width = screen.availWidth - xPos - 50;;
	popupSizePosNormal(url, xPos, yPos, height, width);
}

function popupSizePosNormal(url, xPos, yPos, height, width)
{
	window.open(url, "termsandconditions", "toolbar=yes,location=yes,menubar=yes,resizable=yes,scrollbars=yes,links=yes,status=yes,ScreenX="+xPos+",screenY="+yPos+",height="+height+",width="+width+",left="+xPos+",top="+yPos);
}

function popupMe()
{
	var xPos, yPos;
	var height = "280";
	var width = "450";
	
	if(isNav)
	{
		xPos = opener.window.screenX + 60;
		yPos = opener.window.screenY + 140;
	}
	else
	{	
		xPos = opener.window.screenLeft + 60;
		yPos = opener.window.screenTop;
	}

	popupSizeAndPositionMe(xPos, yPos, height, width);
}

function popupSizeMe(height, width)
{
	var xPos, yPos;
	
	if(isNav)
	{
		xPos = opener.window.screenX + 60;
		yPos = opener.window.screenY + 140;
	}
	else
	{	
		xPos = opener.window.screenLeft + 60;
		yPos = opener.window.screenTop;
	}

	popupSizeAndPositionMe(xPos, yPos, height, width);
}

function popupSizeAndPositionMe(xPos, yPos, height, width)
{
	window.moveTo(xPos, yPos);
	window.resizeTo(width, height);
	if (isNav)
	{	
		window.locationbar.visible = false;
		window.menubar.visible = false;
		window.personalbar.visible = false;
		window.statusbar.visible = false;
		window.toolbar.visible = false;
	}
}
<!-- ++CR_11477 -->
function fnConfirmOptOut(obj)
{
  if(obj.checked)
  {
   if(confirm("Important Notice\n\nIf you tick this box, we will not be able to send you certain information on offers and promotions, such as special discounts with NatWest.\n\nIf you DO wish to receive information on offers and promotions from NatWest or carefully sellected third parties, please click ‘OK’. Otherwise, please click ‘Cancel’."))
   {
    obj.checked=false;
    return true;
   }
   else
   {    

     return false;
   }
  }
 }
 <!-- --CR_11477 -->