function chngStyle(id,style) { document.getElementById(id).className = style; }

function openwin(pref,fname,w,h) {
	sw = screen.width;
	sh = screen.height;
	
	l = sw/2-w/2;
	t = sh/2-h/2;
	window.open(pref+'inc/imageviewer.php?url='+fname,'img','left='+l+', top='+t+', width='+w+', height='+h);
}