Hi Jim,

Arnab's answer will almost get you there... but not quite.

You can change the cascade rule to "None" (note this is not the same as "--None--"), however this will only maintain the value of the sys_id after the referenced record gets deleted.   To store the value of the name field instead, set it (name) as the Reference Key for your reference field in addition to changing the cascade rule.

The thing you have to be aware of is that if you have any duplicate values stored in the 'name' field, this could cause it to point to an incorrect record.   However if your usernames are required to be unique, this shouldn't be a problem.

Give that a try,

-Brian