title: how to rename menu in vtiger crm am trying to do that am getting warnings
body: <p>I am trying to rename the menu items in v tiger crm. I googled but I could not get the right information. I try to change the menu items and getting the following warnings.</p>
  
  <p><code>'contacts'=&gt;'customers' in include/language/en_us.lang.php</code></p>
  
  <p><code>Warning: Cannot modify header information - headers already sent by (output started at ``vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 606</code></p>
  
  <p><code>Warning: Cannot modify header information - headers already sent by (output started at ``/vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 608</code></p>
  
  <p><code>Warning: Cannot modify header information - headers already sent by (output started ``at/vtigercrm/include/language/en_us.lang.php:1) in vtigercrm/index.php on line 610</code></p>