Access, VBA: Find First not working correctly - vba

Question

I hope this is a simple question for someone. I have this method that uses two form fields to check if a record exists in my table and either adds a record or does nothing. So if patient_id is 100, and visit_number is 1, then I will only add a new record if it doesn't already exist.
So, if rst.NoMatch is true - add a new record. However, I can't get it to recognize a duplicate. Here is the code:
Private Sub add_record_button_Click()
Dim rst As DAO.Recordset
Set rst = Me.RecordsetClone
Dim dbs As DAO.Database
Set dbs = CurrentDb
If IsNull(Form.patient_id) Or IsNull(Form.visit_number) = True Then
MsgBox "Please fill in both fields."
Else
rst.FindFirst "[patient_id] = " & Form.patient_id & " And [visit_number] = " & Form.visit_number
If rst.NoMatch Then
Set rst = dbs.OpenRecordset("Visits")
rst.AddNew
rst!patient_id = Form.patient_id
rst!visit_number = Form.visit_number
rst.Update
MsgBox "New patient visit has been added to the database."
Else
MsgBox "That visit already exists."
End If
rst.Close
End If
End Sub
I believe that my FindFirst line isn't correct. In the database, the variables are named patient_id and visit_number. On the form they are named the same.
Any help would be appreciated, thanks.
EDIT.
From the comments below, I was able to get my logic working but using a different compare feature, Dlookup.
IsNull(DLookup("[patient_id]", "MyTable", "[patient_id] = " & Forms("MyForm").patient_id & " AND [visit_number] = " & Forms("MyForm").visit_number)
FINAL EDIT.
The above line made everything work if I used the form directly, however if I put the form into a navigation form - it stopped working. The string that ultimately got it working from within a navigation form looks like this:
If IsNull(DLookup("[patient_id]", "Visits", "[patient_id] = " & Me!patient_id.Value & " AND [visit_number] = " & Me!visit_number.Value)) = True Then
Thank you all for your help.

Answer 1

I've never seen Form used this way, and you should be able to add the record directly in the form, so try:
Private Sub add_record_button_Click()
Dim rst As DAO.Recordset
Set rst = Me.RecordsetClone
Dim PatientId As Variant
Dim VisitNumber As Variant
PatientId = Me!patient_id.Value
VisitNumber = Me!visit_number.Value
If IsNull(PatientId) Or IsNull(VisitNumber) Then
MsgBox "Please fill in both fields."
Else
rst.FindFirst "[patient_id] = " & PatientId & " And [visit_number] = " & VisitNumber & ""
If rst.NoMatch Then
rst.AddNew
rst!patient_id.Value = PatientId
rst!visit_number.Value = VisitNumber
rst.Update
MsgBox "New patient visit has been added to the database."
Else
MsgBox "That visit already exists."
Me.Bookmark = rst.Bookmark
End If
End If
End Sub