function popWindow( url, width, height, windowName )
{
	 var left = (screen.width - width) / 2;
    var top = (screen.height - height) / 2;
    
    win=window.open(url, windowName, 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=1,width=' + width + ',height=' + height + ',left=' + left + ',top=' + top);
win.focus();
}

function info_top( urltop ){popWindow( urltop, 490, 490, "main");}