How to update custom field X when custom field Y changed?

[canyildiz]

I'm trying to give my users to hide two of their custom field informations from another users but not from mods and admins. These two fields are NAME and SURNAME fields. I added another custom field in settings part that gives chance to user for choosing display method for those as following:

1) Full Name and Surname as "NAME SURNAME"
2) Hidden Name as "N SURNAME"
3) Hidden Surname as "NAME S"
4) Hidden Name & Surname as "N S"

What I'm planning is;

I will create two more custom profile fields named "SHOWN_NAME" and "SHOWN_SURNAME". These fields cannot be seen or edited by user. I will use this only in "postbit_legacy" template for other users to see.

I made necessary modifications on "class_profileblock.php" and "class_userprofile.php" to hide NAME and SURNAME fields from other users and show those to user's self only.

But I can't find the code where update process made when user changes a field info. If I can find I will update SHOWN_NAME and SHOWN_SURNAME fields according to new value chosen.

Is there anybody can help me with this? Or is there any easier way to make this? I read too many mods for vb4 in forum but I couldn't find any.

Best Regards,

Can