function viewport() {
		 var viewportwidth;
		 var viewportheight;
		 
		 // the more standards compliant browsers (mozilla/netscape/opera/IE7) use window.innerWidth and window.innerHeight
		 
		 if (typeof window.innerWidth != 'undefined')
		 {
		      viewportwidth = window.innerWidth,
		      viewportheight = window.innerHeight
		 }
		 
		// 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
		 }
		 
        var viewport = new Array(2);		 
		viewport[0] = viewportwidth;
		viewport[1] = viewportheight;
		 
		return viewport;

}