InfoPath Dev

I want a control to always be hidden unless it is one of the three specified users who are in the form.

So, I added a field that will hold the current user name

Then, put a condition on the field I want hidden, to be hidden if Current user is not equal to melissam

That worked just fine. So I proceeded to change the conditional formatting on the control to hide if current user is not equal to user1 or user2 or user3. That conditional formatting did not work. Any suggestions?

Your close... you need to use "and" instead of "or". If you use OR, it will ALWAYS hide because the current user will never be equal to all 3 fields unless all 3 fields are identical. 

currentUser != user1 AND currentUser != user2 AND currentUser != user3 THEN hide control.

How could i do this using a sharepoint list of users?  I have the data connection set up and i'm trying to use a condition similar to this.

If the data connection is with sahrepoint "User Information List", "Account" field is the Reference by which we can set the conditional formatting.

Now set the Conditional formatting to the field which you want to hide this way, saying :

"If Any occurance of Account" (is not equal) username()

then hide this control.

This will hide the control,unless your credential is there in Sharepoint "user information list".

Hope this works fine.