public boolean dialogItemChanged(GenericDialog gd, AWTEvent e) {
        Vector numFields = gd.getNumericFields();
        TextField xNumField = (TextField)numFields.get(0);
        TextField yNumField = (TextField)numFields.get(1);
        Checkbox linkCheckbox = (Checkbox)gd.getCheckboxes().get(0);
        linkXY = gd.getNextBoolean();
        if (linkXY && !xNumField.getText().equals(yNumField.getText())) {
            if (e.getSource() == xNumField  || e.getSource() == linkCheckbox)
                yNumField.setText(xNumField.getText());
            else if (e.getSource() == yNumField)
                xNumField.setText(yNumField.getText());
        }
        type = gd.getNextChoiceIndex();
        xRadius = (int)gd.getNextNumber();
        yRadius = (int)gd.getNextNumber();
        preProcess = gd.getNextChoiceIndex();
        subtract = gd.getNextBoolean();
        offset[impType] = gd.getNextNumber();
        return (!gd.invalidNumber() && xRadius>=0 && yRadius>=0 && xRadius<1000000 && yRadius<1000000);
    }