function openwin(winurl,wwidth,wheight,wscroll) 
{
	var winurl;
	var wwidth;
	var wheight;
	var wscroll;
	if(wscroll=='') wscroll=0;
		popwin = window.open(winurl, '_blank', 'toolbar=0, location=0,  menubar=0, resizeable=0, scrollbars='+wscroll+', width='+wwidth+', height='+wheight);
	popwin.moveTo((screen.width/2)-wwidth/2,(screen.height/2)-wheight/2);
}