Index: txtdb/txtdb.scm
==================================================================
--- txtdb/txtdb.scm
+++ txtdb/txtdb.scm
@@ -270,10 +270,11 @@
 				    (print "ERROR: Unrecognised line in input file " fname ", ignoring it")
 				    (loop (read-line inp) section res))))))))
 
 (define (get-value-type val expressions)
   (cond 
+   ((not val)            '(ValueType "60"))
    ((string->number val) '(ValueType "40"))
    ((equal? val "")      '(ValueType "60"))
    ((equal? (substring val 0 1) "=")
     (let ((exid (hash-table-ref/default expressions val #f)))
       (if exid