Validating Datamanager Values?

[Abhik]

Hello,
I have added two simple html text fields in newthread template and now want to save them using datamanager and show them in the showthread template.

First, I have placed them in GPC Array (in newthread_post_start hook):

PHP Code:

$vbulletin->input->clean_array_gpc('p', array(
    'domainforsalename' => TYPE_STR,
    'domainforsalebnprice' => TYPE_STR,
));
$newpost['domainforsalename'] = $vbulletin->GPC['domainforsalename'];  
$newpost['domainforsalebnprice'] = $vbulletin->GPC['domainforsalebnprice']; 


Second, I added the values (in newpost_process hook):

PHP Code:

$domaindata =& datamanager_init('Thread', $vbulletin, ERRTYPE_ARRAY, 'threadpost');

$domaindata->setr('domainforsalename', $domainforsalename);
$domaindata->setr('domainforsalebnprice', $domainforsalebnprice);

    $domaindata->setr('domainforsalename', $post['domainforsalename']);
    $domaindata->setr('domainforsalebnprice', $post['domainforsalebnprice']);
    
$domaindata->pre_save();
if (count($domaindata->errors) > 0)
{
    // Errors occurred. Do not proceed with the save.
    // You may want to loop through $dataman->errors and 
    // display the results the user.
}
else
{
    // No errors occurred.
    // Proceed with the save (see the next step).
}


$domainforsalename = $domaindata->save();
$domainforsalebnprice = $domaindata->save();

// updating an existing record
$domaindata->save(); 


And, finally validating the data (in threaddata_presave hook):

PHP Code:

$this->validfields['domainforsalename'] = array(TYPE_STR, REQ_NO); 
$this->validfields['domainforsalebnprice'] = array(TYPE_STR, REQ_NO); 


Still I am getting an error;
Fatal error: Field domainforsalename is not defined in $validfields in class vB_DataManager_Thread in [path]/includes/class_dm.php on line 515

What should I do?