If you want the find to limite the results to a specified Filed/In-Use status, then you'll need another global field with the radio button format for specifying that option and another set field step that uses that field to specify your find criteria.
But if you just want to limit the values in the pop-up menu to values with the specified status, you can do that with a conditional value list if you set up the appropriate relationship to support such an option.
I've tried the global field method with a radio button text field. However, (being rather ignorant of global fields) I'm not sure how to display in the pop-up field values from my original gSelectPatientID and the new gPatientStatusList. See script attached. Currently I get a warning that my 'find criteria' aren't valid.
A linked point. Once the above works I may select 'patient A' listed as 'In-use'. I presume I need a second radio button field 'PatientStatus' = File/Use so that I may then click 'File' if I want to change 'Patient A's' status. Should I then calculate PatientStatusList = PatientStatus?
The script looks correct. If you are getting invalid find criteria, I would guess that you don't have these two global fields located on a layout where the user selects/enters a value in one or both of these fields, then clicks a button to perform the above script.
The pop-up is set to display from: Global::gSelectPatientID. This works fine. How do I simultaneously have the pop-up selecting from Global::gSelectPatientStatusList?
You just need both fields on the layout, each with the correct formatting for selecting/entering data so I don't understand your question.
OK, both global fields are on the layout. No problem with the script working, but how do I get 'gSelectPatientStatusList' to, in effect, filter the names listed in the pop-up for 'gSelectPatient', ie. when I select the PatientStatusList field = Filed, only patients who have been filed get listed in the 'gSelectPatientStatusList' pop-up?
Ok, you need a conditional value list. That typically requires a relationship where the field with the first value list is used as the match field.
Here are some links on the subject of conditional value lists.
There's a lot of overlap between the first two links so you can read one and skim the other. The demo file gives you several examples of different conditional value lists so you can examine them to see how they are set up. If you are using FileMaker 12, you can open this demo file from your File menu to get a converted copy of the demo file that you can examine in FileMaker 12.
The last link discusses how to set up a chain of conditional value lists where the value selected in each conditional value list controls the values listed in the next value list.
Forum Tutorial: Custom Value List?
Knowledgebase article: http://help.filemaker.com/app/answers/detail/a_id/5833/kw/conditional%20value%20list
Hierarchical Conditional Value lists: Conditional Value List Question
Feel free to post follow up questions here if those links aren't enough to get your value lists working correctly.