Todd,
Have you looked into the Oldval() and CurVal() functions? These will tell you if a field has been changed by the user.

Also, Getfldstate(Fieldname) will tell you if it has been changed.

HTH
Barbara

>Hmmm... Let me step back a step then, maybe there is another way than a custom property...
>
>What I really want to do is to run some code in my valid event if the user has changed the value of the text box. (Basically, it does a lookup into another table and fills fields based off the current ssn.) But if the user doesn't make a change to the ssn, I would rather not run the code.
>
>So, what is the best way to tell if a user has changed the value of a text box during the valid event?