Index: openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl,v
diff -u -N -r1.65 -r1.66
--- openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl	28 Jun 2015 19:07:18 -0000	1.65
+++ openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl	28 Jun 2015 19:24:42 -0000	1.66
@@ -1164,7 +1164,7 @@
 
 		    upvar #$level __new_p __new_p
 
-		    if {![string is boolean -strict $__new_p]} {
+		    if {[info exists __new_p] && ![string is boolean -strict $__new_p]} {
 			ad_return_complaint 1 "Your request is invalid."
 			ns_log Warning "Validation error in hidden form element.\
 		This may be part of a vulnerability scan or attack reconnaissance: fish values __new_p"