var	maxWid = screen.availWidth;
var	maxHei = screen.availHei;

function wopen(url){
	wWid = 800;
	wHei = 700;
	wLeft = (maxWid - wWid)/2;
	wTop = (maxHei - wHei)/2;
	window.open(url,'','top='+wTop+',left='+wLeft+',scrollbars=yes,resizable=yes,width='+wWid+',height='+wHei+',status=no');
}