<script>
 
    var dhxWins = new dhtmlXWindows();
    ...
    // bringing window to top
    dhxWins.window(id).bringToTop();
    // is window on top
    var onTop = dhxWins.window(id).isOnTop(); // true/false
    // bringing window to bottom
    dhxWins.window(id).bringToBottom();
    // is window on bottom
    var onBottom = dhxWins.window(id).isOnBottom(); // true/false</script>