how to display custom field in forum

[changtraingheo]

PHP Code:

if ($vbulletin->userinfo['fieldX'])  //Check if you put the name to display
$vbulletin->userinfo['username'] = $vbulletin->userinfo['fieldX']; 


Thanks your help, but this code only work when i logined and i only can see Display Name of me .. What i mean is that apply for all account, example when i view profile of another user, if display name of that user not be empty then i see display name of that user not account name of that user ...

Example this forum, my account is changtraingheo, when i enter display name is Mr Phi, when u refresh page, u can not see changtraingheo, u only see Mr Phi.

Sr, my english is not good ^^