QDialog - customize the buttons

[ape]

Hello

i have implemented my About this app window using Qdialog
so basically i get a small popup which displays some informations about my app.

Code example:

QDialog about(this);
about.setModal(true);
about.setWindowTitle(tr("About my app"));
about.setLayout(mainLayout);

QDialog about(this);
about.setModal(true);
about.setWindowTitle(tr("About my app"));
about.setLayout(mainLayout);

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Using this code i get a small window with 2 window-control buttons in the head:
1 x X to close the window
1 x ? which can be used for helpdialogs.

Can i get rid of this question-mark button in the qdialog window ?
Best regards in advance