Bring widget at the back of another widget

[LovelyGrace]

I have created a widget that whenever the mainwindow runs, it will also display. but the problem is that when another widget is executed, this widget keeps displayin in front. I want the widget to be at the back of any widget that will be executed and remains background like the mainwindow.

as of now this is the code of the widget that runs the same time as the mainwindow:
ui->setupUi(this);
this->setFocusPolicy(Qt::NoFocus);
this->setWindowFlags(Qt::X11BypassWindowManagerHint);
this->setFixedSize(400, 100);
this->move(500, 600);

[SamurayH]

I can guess that you're trying to change your widgets' Z-order. If so, check out the following functions :
QWidget::stackUnder, QWidget::raise and QWidget::lower.

Hope it helps.