User Permissions

Hello,

I have a function that I've written in plpgsql.  In it I lock a table 
before selecting a value and, depending on the value, either update the 
record selected or insert a new one.  It works perfectly when I run it as a 
super-user or as the owner of the table.  However, as a standard user I am 
unable to lock the table.  How do I either run the function at the owners 
level, or change the permissions on the table to allow the user to lock it?

I am unable to lock the table as a standard user at any time, not just when 
running the function.

Thanks in advance,

Braum Meakes