GridData data = new GridData(GridData.FILL_BOTH);
composite.setLayoutData(data);
composite.setFont(parent.getFont());
DialogPage page= new MessageDialogPage((Composite)composite) {
public void setErrorMessage(String newMessage) {
super.setErrorMessage(newMessage);
setButtonEnabledState(IDialogConstants.OK_ID, newMessage == null);
setButtonEnabledState(APPLY_ID, newMessage == null);
}