Changed the submit function to use the new pieform model for replying

to ajax posts. Corrected the blanking of the password fields

htdocs/account/index.php

@@ -141,9 +141,9 @@ $smarty = smarty();
 $smarty->assign('form', pieform($prefsform));
 $smarty->assign('INLINEJAVASCRIPT', "
 function clearPasswords() {
-    $('oldpassword').value = '';
-    $('password1').value = '';
-    $('password2').value = '';
+    $('accountprefs_oldpassword').value = '';
+    $('accountprefs_password1').value = '';
+    $('accountprefs_password2').value = '';
 }");
 $smarty->display('account/index.tpl');
 
@@ -161,7 +161,7 @@ function accountprefs_validate(Pieform $form, $values) {
     }
 }
 
-function accountprefs_submit($values) {
+function accountprefs_submit($values, Pieform $form) {
     global $USER;
 
     db_begin();
@@ -185,8 +185,7 @@ function accountprefs_submit($values) {
     }
 
     db_commit();
-    json_reply(false, get_string('prefssaved', 'account'));
-    exit;
+    $form->json_reply(PIEFORM_OK, get_string('prefssaved', 'account'));
 }