Index: openacs-4/packages/file-storage/www/download-zip.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/file-storage/www/download-zip.tcl,v
diff -u -r1.6.6.2 -r1.6.6.3
--- openacs-4/packages/file-storage/www/download-zip.tcl	1 Apr 2014 18:37:32 -0000	1.6.6.2
+++ openacs-4/packages/file-storage/www/download-zip.tcl	5 Aug 2014 17:46:33 -0000	1.6.6.3
@@ -1,7 +1,7 @@
 ad_page_contract {
     delete items
 } {
-    object_id:notnull,multiple
+    object_id:naturalnum,notnull,multiple
     {confirm_p:optional,boolean 0}
     {return_url ""}
 } -errors {object_id:,notnull,integer,multiple {Please select at least one item to download.}