reference in same table

Hi!
Can I implement a reference from a foreign key  to a  primary key field  
in the same table?
I try the something like this:
<table id="users" name="Users" field-prefix="User" qualifier="test_" 
fixed="false" signed="false" suffix="">
            <field id="userid" name="ID" type="int" primary-key="true" />
            <!-- <field id="bossid" name="bossID" type="int" /> -->
            <field id="username" name="Name" type="NVARCHAR(30)" 
nullable="false" />
            <field id="userlastname" name="LastName" type="NVARCHAR(30)" 
nullable="true" />
            <reference id="ref_myBoss" ref-table="users" field-prefix="" 
nullable="false" match="userid" name="bossid" />
            <!-- <reference id="ref_myBoss" ref-table="users" 
field-prefix="" nullable="false" name="bossid"/> -->
</table>
but I get error that a "duplicate field name while creating foreign 
keys" was found.
Could you help me?

What make the match and name attribute in reference-type tag exactly?

Thank you!


-------------------------------------------------------
This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek
For a limited time only, get FREE Ground shipping on all orders of $35
or more. Hurry up and shop folks, this offer expires April 30th!
http://www.thinkgeek.com/freeshipping/?cpg=12297