function windowURLCentered(url, winwidth, winheight, param)
{
	var date = new Date();
	var name = date.getTime();

	var win = openWinCentered(name, url, winheight, winwidth, param);
}
function openWinCentered(winname, loc, heightt, widthh, params)
{  
	tp=Math.ceil((screen.height-heightt)/2);
	lf=Math.ceil((screen.width-widthh)/2);
	if (params.length > 0) params = "," + params;
	return window.open(loc,winname,"width="+widthh+",height="+heightt+",top="+tp+",left="+lf+params);
}