#2 SendingDialog appears in the upper-left corner of the screen

[Jip]

The sending dialog should appear at the center of the
application frame. Instead, it appears in the
upper-left corner of the screen. This is not good.

I checked the following references:
http://java.sun.com/docs/books/tutorial/uiswing/components/dialog.html
http://java.sun.com/j2se/1.5.0/docs/api/javax/swing/JDialog.html#JDialog\(java.awt.Frame,%20boolean)

In SendingDialog constructor, I transfer the
application frame to the parent constructor. I believed
this would work. It does not.

Do you have any idea why ?