void setStrands() throws ScriptException {
		int strandCount = 5;
		if (statementLength == 3) {
			if (statement[2].tok != Token.integer)
				integerExpected();
			strandCount = statement[2].intValue;
			if (strandCount < 0 || strandCount > 20)
				numberOutOfRange(0, 20);
		}
		viewer.setShapeProperty(JmolConstants.SHAPE_STRANDS, "strandCount", new Integer(strandCount));
	}