VBA getConfig: retreive key:value from a config sheet

Function getConfig(key As String) As String
    Dim i As Integer
    Dim xKey As String, strFila As String
    Dim sh
    
    Set sh = Sheets("config")
    
    For i = 1 To 500
        strFila = Trim(Str$(i))
        xKey = sh.Range("A" + strFila).Value
        
        If (key = xKey) Then
            getConfig = sh.Range("B" & strFila).Value
            Exit Function
        End If
        
        If (xKey = "[end]") Then Exit For
    
    Next i
    
    MsgBox "ERROR key not found in config page: [" & key & "]", _
         vbOKOnly + vbCritical, "ERROR"

    End
End Function