var count1 = 47;
var count2 = 15;

function showShot1(img)
{

var screenWidth1		=	(screen.width - 700) / 2;
var screenHeight1	=	(screen.height - 588) / 2;

page = "screens.jsp?num=" + count1;
window.open(page,'','scrollbars=0,height=588,width=700,top='+screenHeight1+',left='+screenWidth1+'');
}

function forwardScreen1(img)
{
		count1 = count1 - 1;
		 if(count1 == 0)
			count1 = 47;

	document[img].src = "images/screens/screen" + count1 + "s.gif";

}

function backScreen1(img)
{
		count1 = count1 + 1;
		 if(count1 == 48)
			count1 = 1;

	document[img].src = "images/screens/screen" + count1 + "s.gif";

}


function showShot2(img)
{

var screenWidth2		=	(screen.width - 700) / 2;
var screenHeight2	=	(screen.height - 588) / 2;

page = "concepts.jsp?num=" + count2;
window.open(page,'','scrollbars=0,height=588,width=700,top='+screenHeight2+',left='+screenWidth2+'');
}

function forwardScreen2(img)
{
		count2 = count2 - 1;
		 if(count2 == 0)
			count2 = 15;

	document[img].src = "images/concepts/screen" + count2 + "s.gif";

}

function backScreen2(img)
{
		count2 = count2 + 1;
		 if(count2 == 16)
			count2 = 1;

	document[img].src = "images/concepts/screen" + count2 + "s.gif";

}