UPDATE in MySQL

[admin]

I am unable to update a record with:
mysql_query ("UPDATE table SET column=Y WHERE User_ID = $userid");
$userid comes from a form

I am able to do this from the command line but not from the web.

I have even tried with this before the UPDATE query:
mysql_query ("GRANT UPDATE (column) ON database.table to $userid");

This doesn't help either.

I've tried w/o the mysql_query as well.

Is this a permissions issue? If so, how do I grant permissions to the specific user within the php script called (not in a user priviledge table)?

Thanks in advance,
gary