Add little validation with property not found

gulliver/system/class.dynaformhandler.php

@@ -384,6 +384,7 @@ class dynaFormHandler
         }
         foreach ($av as $e) {
             $xnode = $this->root->getElementsByTagName($e)->item(0);
+            if (isset($xnode->nodeType)) {
                 if ($xnode->nodeType == XML_ELEMENT_NODE) {
                     $dropednode = $this->root->removeChild($xnode);
                     /* evaluation field aditional routines */
@@ -396,6 +397,9 @@ class dynaFormHandler
                 } else {
                     print("[Class dynaFormHandler] ERROR:  The \"$e\" element doesn't exist!<br>");
                 }
+            } else {
+                print("[Class dynaFormHandler] ERROR:  The \"$e\" element doesn't exist!<br>");
+            }
         }
         $this->save();
     }