public void print(String s,AST t) {
        // assume less than 1000 nodes; no problem for csc 413
        int num = t.getNodeNum();
        AST decoration = t.getDecoration();
        int decNum = (decoration == null)? -1 : decoration.getNodeNum();
        String spaces = "";
        if (num < 100) spaces += " ";
        if (num < 10) spaces += " ";
        System.out.print(num + ":" + spaces);
        printSpaces(indent);
        if (decNum != -1) {
            s += "           Dec: " + decNum;
        }
        String lab = t.getLabel();
        if ( lab.length() > 0 ) {
            s += "  Label: "+t.getLabel();
        }
        if (t.getClass() == IdTree.class) {
            int offset = ((IdTree)t).getFrameOffset();
            if (offset >= 0) {
                s += "  Addr: " + offset;
            }
        }
        System.out.println(s);
        indent += 2;
        visitKids(t);
        indent -= 2;
    }