' FB 1.05.0 Win64

Enum ErrorType
  myError = 1000
End Enum

Sub foo()
  Err = 1000 ' raise a user-defined error
End Sub

Sub callFoo()
  foo()
  Dim As Long errNo = Err ' cache Err in case it's reset by a different function
  Select Case errNo
    Case 0
      ' No error (system defined)
    Case 1 To 17
      ' System defined runtime errors
    Case myError:   ' catch myError
      Print "Caught myError : Error number"; errNo
    Case Else
      ' catch any other type of errors here
  End Select
  ' add any clean-up code here
End Sub

callfoo()
Print
Print "Press any key to quit"
Sleep