private String useSystemVariables(String s) {
		s = replaceAll(s, "%model_time", model.modelTime);
		s = replaceAll(s, "%number_of_atoms", model.getAtomCount());
		s = replaceAll(s, "%number_of_rbonds", model.getRBondCount());
		s = replaceAll(s, "%number_of_abonds", model.getABondCount());
		s = replaceAll(s, "%number_of_tbonds", model.getTBondCount());
		s = replaceAll(s, "%number_of_molecules", model.getMoleculeCount());
		s = replaceAll(s, "%number_of_obstacles", model.getObstacleCount());
		s = replaceAll(s, "%width", model.view.getWidth());
		s = replaceAll(s, "%height", model.view.getHeight());
		s = replaceAll(s, "%cell_length", model.getLength());
		s = replaceAll(s, "%cell_width", model.getWidth());
		s = replaceAll(s, "%cell_height", model.getHeight());
		s = replaceAll(s, "%loop_count", iLoop);
		s = replaceAll(s, "%loop_times", nLoop);
		s = replaceAll(s, "%index_of_selected_atom", model.view.getIndexOfSelectedAtom());
		s = replaceAll(s, "%temperature", model.getTemperature());
		s = replaceAll(s, "%mouse_x", mouseLocation.x);
		s = replaceAll(s, "%mouse_y", mouseLocation.y);
		s = replaceAll(s, "%keycode", keyCode);
		return s;
	}