not sure why you want buttons for delete and add?
look at the screenshot of an applicant candidate system.
the STATUS is a portal. just clicking the calandar and pull down list will generate a new record.
(delete record = clear values)
how to get it like this? design the portal. then for the disease field (in your case) use the inspector and select in stead of EDIT BOX
I would not remove diseases from the portal, just mark them as "inactive" in order to preserve the patient's medical history. Best is to have a tab with "Current diseases" and "all diseases".
While you're on a patient record, show an ICD 10 list in a cartesian portal. Clicking on a line will create a new record in PatientDiseases with dateStart to be inputted and you can subsequently mark it as "past" as of "dateEnd", which will move it to the inactive portal.
This is the functionality. The implementation is quite simple, involving a CreateDisease[patID, ICD10Code] script which you call passing the 2 parameters. The script will freeze window, go to a PatientDiseases table based layout, create a new record, set the 2 fields, commit and come back to the Patient layout.