Index: misc/ajax.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/ajax.js,v
retrieving revision 1.15
diff -u -r1.15 ajax.js
--- misc/ajax.js	7 Apr 2010 17:30:43 -0000	1.15
+++ misc/ajax.js	7 Apr 2010 19:48:44 -0000
@@ -172,8 +172,8 @@
   // action.
   if (element_settings.keypress) {
     $(element_settings.element).keypress(function (event) {
-      // Detect enter key.
-      if (event.keyCode == 13) {
+      // Detect enter key and space bar.
+      if (event.which == 13 || event.which == 32) {
         $(element_settings.element).trigger(element_settings.event);
         return false;
       }