ChooseVariableDialog dialog= new ChooseVariableDialog(getShell());
ChooseVariableDialog dialog= new ChooseVariableDialog(getShell(), fLastVariableSelection);
	private String chooseVariable() {		ChooseVariableDialog dialog= new ChooseVariableDialog(getShell());		if (dialog.open() == dialog.OK) {			return 	dialog.getSelectedVariable();		}				return null;			}		