var viewportWidth;
var viewportHeight;

function getViewportSize()
{
	// the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
	 
	if (typeof window.innerWidth != 'undefined')
	{
		viewportWidth = window.innerWidth; // includes scrollbars in Firefox
//		viewportWidth = document.documentElement.clientWidth;
		viewportHeight = window.innerHeight;

//		viewportWidth = document.body.clientWidth;

		if (document.body.scrollHeight > document.body.clientHeight)
		{
			viewportWidth = document.body.clientWidth;
		}
		

//		viewportWidth = window.innerWidth; // includes scrollbars in Firefox		
	}
	 
	// IE6 in standards compliant mode (i.e. with a valid doctype as the first line in the document)

	else if (typeof document.documentElement != 'undefined'
		 && typeof document.documentElement.clientWidth !=
		 'undefined' && document.documentElement.clientWidth != 0)
	{
		viewportWidth = document.documentElement.clientWidth,
		viewportHeight = document.documentElement.clientHeight
	}
	 
	// older versions of IE
	 
	else
	{
		viewportWidth = document.getElementsByTagName('body')[0].clientWidth,
		viewportHeight = document.getElementsByTagName('body')[0].clientHeight
	}
}