Enabling ESS user to enter Bank information

Hi All,

  I am new to SAP portal 7.3 version. My requirement is to make the ess user to enter his/her bank details for the first time and after that this should not be editable. But in the portal there is no option to add the bank details as like in others( ie. ADD option in ADDRESSES).

  How to make it available?

Thanks in Advance

Vengadesh R