DLookUp Flashing Error

[RawToast]

Hello,
I managed to solve this issue on my own, but I thought I would post my experience here in hopes that it might be useful to someone else. I made a form for a table which contains client questionnaire responses, "Dec4Docs". I wanted to include the names of these clients in the form, just to make everything easier for whoever is doing data entry, but client names are in a different table, "BasicInformation". Both the questionnaire table and the client information table use a common ID number, "WISnum". I found a
number of online tutorials which instructed me to use the DLookUp function for what I'm doing.

This site here, for example, suggests the following formula:

=DLookup("CustomerID", "Orders", "OrderID = " & Forms![Orders]!OrderID)

Which I adapted to:

=DLookUp("FirstName","BasicInformation","WISnum=" & [Forms]![Dec4DocsForm]![WISnumField])



^This was meant to find FirstName in the BasicInformation table where WISnum is equal to the WisnumField of the Dec4DocsForm form. Instead, all I got was a flashing error message that partially broke the program's GUI. I could not find a solution on Google, so I played around for awhile, bug checking by adding and removing things to the formula, until I finally got a little lucky and figured this out:

=DLookUp("FirstName","BasicInformation","WISnum=" & '[Forms]![Dec4DocsForm]![WISnumField]')

I hate that this was the solution. It still feels wrong. Practically speaking, this seems to be good enough for what I'm doing. I hope it is good enough for whoever finds this post.

Let me know if you found this helpful, or if there is a better way to do this. Unfortunately, I cannot post my database because it contains sensitive client information.

[RuralGuy]

Here's the usual way to specify a string:
=DLookUp("FirstName","BasicInformation","WISnum='" & [Forms]![Dec4DocsForm]![WISnumField] & "'")