void setSsbond() throws ScriptException {
		checkLength3();
		boolean ssbondsBackbone = false;
		viewer.loadShape(JmolConstants.SHAPE_SSSTICKS);
		switch (statement[2].tok) {
		case Token.backbone:
			ssbondsBackbone = true;
			break;
		case Token.sidechain:
			break;
		default:
			invalidArgument();
		}
		viewer.setBooleanProperty("ssbondsBackbone", ssbondsBackbone);
	}