function winOpen(url, windowname, wid, hei){
	var futures = "width="+wid+",height="+hei;
	var rndNum = Math.floor(Math.random()*10000);
	var urldummy = url+"?dummy="+rndNum;
	var fset = window.open(urldummy, windowname, futures);
	var w = screen.width;
	var h = screen.height;
	var dw = (w - wid)/2;
	var dh = (h - hei)/2;
	fset.moveTo(dw, dh);
	fset.focus();
}