How to pause execution while JDialog is open

Simply use:

setModal(true);

I usually call it from within the constructor of the JDialog.

See the Javadocs on setModal(boolean).
http://java.sun.com/javase/6/docs/api/java/awt/Dialog.html#setModal(boolean)

That will cause execution to block on the current thread until the dialog box closes.

Alternatively, you can use:

setModalityType(Dialog.DEFAULT_MODALITY_TYPE);

It is equivalent to setModal(true) and technically the correct way to do it.