It looks like you're using a datasheet form. If so, I would put the field that holds the receipt location in the header or footer of that form (the form in the sub form). Even though Form Header and Form Footer aren't visible for datasheet forms, you can still use them for hidden fields. It's a good way to make sure that the user can't right-click and "unhide" the field in the datasheet.

Then, getting the location into that field in the subform is as easy as adding it to your attach picture routine, such as:
SUBFORMNAME.Form!ReceiptLocation = ReceiptLocation
* Update Control names as appropriate

For the "ReceiptPicture" column, I would have an unbound field with the source:
=iif(nz(ReceiptLocation,"")<>"","View Receipt","")
and be sure to "Lock" the field so it can't be edited.

In the "On Click" event of the Receipt Picture field, I would again verify that there is a file location and that it's valid. If not valid, just exit the sub and do nothing. If it is valid, you could do something like Follow Hyperlink to open the appropriate file.

Donald, that is truly amazing!  I never thought of it that way, but it works perfectly.  Thanks....Learned something new tody.

glad it worked out for you :)

As a side note, hidden Headers/Footers can come in handy on regular forms too. While working on projects, I will often put a "Debug Mode" toggle on the main menu. When set to on, it sets a "DebugMode" = True TempVar. Then in forms, if I'm not using either a header or footer, I'll place any hidden fields there and even leave labels if there are more than a couple so I know what I'm looking at.

Then when a form loads, check if TempVars!DebugMode = True and if so, show the Header and I can see all the hidden fields at once without having to toggle any individual control visibility. If it's false, the entire header or footer is invisible so saves manually toggling then while testing forms and functions.

Glad to see Donald steered you in a good direction here. Using the hidden form headers and footers for storing stuff like file paths is a slick move, even in datasheet forms where you don't want the field just lying around for users to mess with. His approach of storing the file path and then using a field to launch the file with FollowHyperlink is spot on for what you want.

Once you've got the file path stored, it really is as simple as having a clickable label or button in your datasheet to let the user view the file later. Just be sure you've got some error checking in your code for when the file gets moved or deleted. That way, you don't strand your users on a broken path - nobody wants to go looking for receipts in the forbidden zone. Just a quick If Dir(YourFilePath) <> "" check in VBA before FollowHyperlink will save some headaches.

Donald's tip about using DebugMode and toggling headers/footers for dev stuff is great, too. That kind of extra trick can really help keep forms tidy while you're working on more "behind the scenes" stuff.

And yeah, Donald, I'll be stealing… er… I mean "borrowing" that one for a future lesson. :)

Richard Another related trick I've started using:

If I have a several hidden fields and can't just use the form header or form footer, once I've got the form working fairly well, I'll turn on the form's PageHeader or PageFooter... I'll use code to stop the form from being printed, but that way, the fields aren't cluttering my form area and they're still available for code. Granted they won't show on screen during debugging, but I can log what I need in your StatusBox.

Brilliant. I never thought of that. I'd just use TempVars. :)