Index: insert.js
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/insert/insert.js,v
retrieving revision 1.1
diff -u -r1.1 insert.js
--- insert.js	21 Oct 2009 06:23:43 -0000	1.1
+++ insert.js	21 Oct 2009 23:45:04 -0000
@@ -39,7 +39,9 @@
     for (var fieldName in settings.fields) {
       var fieldValue = $(settings.fields[fieldName], wrapper).val();
       var fieldRegExp = new RegExp('__' + fieldName + '__', 'g');
-      content = content.replace(fieldRegExp, fieldValue);
+      if (fieldValue) {
+        content = content.replace(fieldRegExp, fieldValue);
+      }
     }
     // Cleanup unused replacements.
     content = content.replace(/__([a-z0-9_]+)__/g, '');