@theDBguy - if not on a corporate-domain network then there is nothing to automatically load the environment variable "Username" when logging in. The #Name error means that "Username" cannot be found among the environment strings, not that the Environ function failed because it was not defined.
@shery1995 - the problem with debugging an app like this at home is that you are probably not in the right environment for everything to be set up properly. When you are logged in to a corporate domain, the function suggested by theDBguy would work OK to identify you. However, at home you are simply Owner.
The NORMAL way to do this if you are on a corporate network is that you have a domain. You log in to the domain and your IT staff sets up scripts on your behalf (usually, that you don't even know exist, sneaky devils that they are) to define various environmental parameters so that security software (that they also won't tell you about) can identify you if they have to report you for security transgressions.
IF you have this domain environment, then your login name (to the domain) because the Username string. In that case, you could use it to look up stuff from your Users table.
For the purposes of testing, click your Windows icon at the far left of the bottom task bar. From there select Windows System. From there, click on the Command Prompt. To the prompt which depends on your machine configuration and therefore is somewhat unpredictable by me, type
SET Username = Shery1995
Then in your test table, have a lookup name associated with "Shery1995" and you would then be able to test your code using the method suggested by theDBguy.
As an aside, developing stand-alone at home is OK if your boss says it is OK, but if you are going to start sharing your DB with others, you should really make yourself familiar with splitting a database. There are tons of articles on this forum on that subject so you should be able to find out all you need with a simple search. The SEARCH function is near the top of the page, the right-most thing on the same bar that has your forum name in it. Don't search for just "SPLIT" because there is a function by that name. Use the advanced search and seek "splitting database."
