@@ -65,14 +65,15 @@
 		      (loop hed tal depth (+ nodenum 1)))))
 	    #f))))
 
 ;; top is the top node name zeroeth node VALUE=0
 (define (tree:add-node obj top nodelst #!key (userdata #f))
-  (if (not (iup:attribute obj "TITLE0"))
+  (if (or (not (string? (iup:attribute obj "TITLE0")))
+	  (string-null? (iup:attribute obj "TITLE0")))
       (iup:attribute-set! obj "ADDBRANCH0" top))
   (cond
-   ((not (string=? top (iup:attribute obj "TITLE0")))
+   ((not (equal? top (iup:attribute obj "TITLE0")))
     (print "ERROR: top name " top " doesn't match " (iup:attribute obj "TITLE0")))
    ((null? nodelst))
    (else
     (let loop ((hed      (car nodelst))
 	       (tal      (cdr nodelst))