--- prepopulateOld.module	2009-10-28 16:38:36.000000000 -0400
+++ prepopulate.module	2009-11-23 16:27:30.000000000 -0500
@@ -30,6 +30,13 @@ function prepopulate_form_alter(&$form, 
     parse_str(base64_decode($_REQUEST['pp']), $_REQUEST);
   } 
   if (isset($_REQUEST['edit'])) {
+
+    // output debugging info
+    
+    if (isset($_REQUEST['prepopulate-debug'])) {
+  		drupal_set_message(_prepopulate_debug_walk(&$form,'edit'));
+    }
+
     foreach (array_keys((array)$_REQUEST['edit']) as $requestvar) {
       if (element_child($requestvar) && !is_null($form[$requestvar])) {
         _prepopulate_request_walk($form[$requestvar], $_REQUEST['edit'][$requestvar]);
@@ -39,6 +46,32 @@ function prepopulate_form_alter(&$form, 
 }
 
 /**
+ * Internal helper that dumps out possible edit form values
+ * that might be settable
+ *
+ * @param &$form
+ *   Array. A form element.
+ * @param $prefix
+ *   String. Prefix to add to whatever values we find, passed
+ *   down in the recursive traverse.
+ */
+function _prepopulate_debug_walk( & $form, $prefix) {
+
+  $result = '';
+  
+  foreach ($form as $index => $value) {
+    if (is_array($value) && ($index{0} != '#')) {
+      $result .= _prepopulate_debug_walk(&$value,$prefix . '[' . $index . ']');
+    } elseif ($index == '#type') {
+      $result .= $prefix . ' (' . $value . ')<br />' . "\n";
+    }
+  }
+
+  return $result;
+  
+}
+ 
+/**
  * Internal helper to set element values from the $_REQUEST variable.
  *
  * @param &$form