Hi, Andrea,
it is usual browser behavior. There are some HTML objects (called windowed objects) that are displayed in a kind of its own window and some of them have no ability to switch this view mode off: iframe and select (i.e. dropdown menu). These objects cannot be overlapped by any other (non-windowed) objects, even they have larger z-index. Similar objects are Windows Media Player and Flash Player, but they have ability to work in windowless mode (or transparent mode in Flash Player).
Of course there exists workaround (placing any object in front of empty iframe of corresponding size), but this solution is quite hungry for browser resources: it works on simple HTML pages but when it comes to real course... Therefore we do not implement it.
Just try to avoid such overlaps.
Hi, Andrea,
it is usual browser behavior. There are some HTML objects (called windowed objects) that are displayed in a kind of its own window and some of them have no ability to switch this view mode off: iframe and select (i.e. dropdown menu). These objects cannot be overlapped by any other (non-windowed) objects, even they have larger z-index. Similar objects are Windows Media Player and Flash Player, but they have ability to work in windowless mode (or transparent mode in Flash Player).
Of course there exists workaround (placing any object in front of empty iframe of corresponding size), but this solution is quite hungry for browser resources: it works on simple HTML pages but when it comes to real course... Therefore we do not implement it.
Just try to avoid such overlaps.