An empty field's value IS valid and thus that function won't work.
But there's a function called IsEmpty() that you can use:
IsEmpty ( Orders::JobNumber )
Should do the trick unless you need to check and see if the folder named in the JobNumber field exists. That's not something FileMaker can really do without the help of a plug in unless you use a folder located inside the local computer's document folder. (You could try saving or exporting a file to that location and the error message that interrupts your script would tell you, but that's hardly the way to hide this button....)
Yeah, unfortunately, I'm trying to do the latter. I wanted to check if the folder existing on the server, and if it did, then show the icon.
Even if you have to buy it, is there a good site for plug-ins, or at least somewhere I can do some research.
Thanks for your help.
A web search for "FileMaker Plug IN" should pull up a number of Hits. A plug in that can list the contents of a file folder has been created by several different parties. One that I recall by MooPlug is a windows only but free plug in. Troi is the name of another well known long established source of plug ins that includes a plug in for file manipulation.
Grumble at FileMaker: If I could use Set Error Capture to supress the error dialog that pops up when Export Records tries to create a record and fails, I could do this pretty much all in FilMaker (except for maybe a system script to delete the record created when Export Records succeeds in creating the file...)
System Scripts, BTW, are the other way that you can do this. A system script (system scripts are dependent on your operating system as to which you can use) can generate a text file listing a folder's contents and this text file can then be imported into FileMaker in order for a script to then check against that list to see if a file or folder exists in that list.