diff --git a/lib/formslib.php b/lib/formslib.php
index 273a07c33f8..e240934420c 100644
--- a/lib/formslib.php
+++ b/lib/formslib.php
@@ -2220,7 +2220,7 @@ function validate_' . $this->_formName . '_' . $escapedElementName . '(element)
   ret = validate_' . $this->_formName . '_' . $escapedElementName.'(frm.elements[\''.$elementName.'\']) && ret;
   if (!ret && !first_focus) {
     first_focus = true;
-    frm.elements[\'id_error_'.$elementName.'\'].focus();
+    document.getElementById(\'id_error_'.$elementName.'\').focus();
   }
 ';