MIGRATED TO http://wavelet.asia/customer-portal/2011/03/17/permission-setting/

• System Admin > Manage Users > Role Permissions
  
• Select the Role, you want to grant permission for, from the drop-down list.
• Click Customer from the toolbar.

• The page will be displayed in 2 columns.
• Under General Permissions on your left, click General Customer Module Permissions.
• Then check Credit Memo Permissions option on your right. Click 'Submit'. (Example: Click Permission to create Credit Memo by GL Code if you want to enable permission to create Credit Memo by GL)