var popwin=false
function showwin(page,w,h,scroll){
if (popwin.open){
	popwin.close();
	popwin=window.open(page ,'Pages','width=' + w + ',height=' + h + ',left=0,top=0,scrollbars=' + scroll + ',resize=no');
}
	popwin=window.open(page ,'Pages','width=' + w + ',height=' + h + ',left=0,top=0,scrollbars=' + scroll + ',resize=no');

}





function changeImage(filename)
{
   document.mainimage.src = filename;
}