B4J Tutorial WebApps - Let's create a Morse Code Translator

Sub MorseKeys As Map
    Dim table As Map = CreateMap()
    table.Put("A", ".-")
    table.Put("B", "-...")
    table.Put("C", "-.-.")
    table.Put("D", "-..")
    table.Put("E", ".")
    table.Put("F", "..-.")
    table.Put("G", "--.")
    table.Put("H", "....")
    table.Put("I", "..")
    table.Put("J", ".---")
    table.Put("K", "-.-")
    table.Put("L", ".-..")
    table.Put("M", "--")
    table.Put("N", "-.")
    table.Put("O", "---")
    table.Put("P", ".--.")
    table.Put("Q", "--.-")
    table.Put("R", ".-.")
    table.Put("S", "...")
    table.Put("T", "-")
    table.Put("U", "..-")
    table.Put("V", "...-")
    table.Put("W", ".--")
    table.Put("X", "-..-")
    table.Put("Y", "-.--")
    table.Put("Z", "--..")
    table.Put("Á", ".--.-")            'A with acute accent
    table.Put("Ä", ".-.-")            'A with diaeresis
    table.Put("É", "..-..")            'E with acute accent
    table.Put("Ñ", "--.--")            'N with tilde
    table.Put("Ö", "---.")            'O with diaeresis
    table.Put("Ü", "..--")            'U with diaeresis
    table.Put("1", ".----")            
    table.Put("2", "..---")
    table.Put("3", "...--")
    table.Put("4", "....-")
    table.Put("5", ".....")
    table.Put("6", "-....")
    table.Put("7", "--...")
    table.Put("8", "---..")
    table.Put("9", "----.")
    table.Put("0", "-----")
    table.Put(",", "--..--")        'comma
    table.Put(".", ".-.-.-")        'period
    table.Put("?", "..--..")        'question mark
    table.Put(";", "-.-.-")            'semicolon
    table.Put(":", "---...")        'colon
    table.Put("/", "-..-.")            'slash
    table.Put("-", "-....-")        'dash
    table.Put("'", ".----.")        'apostrophe
    table.Put("()", "-.--.-")        'parenthesis
    table.Put("_", "..--.-")        'underline
    table.Put("@", ".--.-.")        'at symbol from http://www.learnmorsecode.com/
    table.Put(" ", "   ")    '3 spaces
    Return table
End Sub

Sub TranslateToMorse(content As String) As String
    Dim mkeys As Map = MorseKeys
    'we will assign everything to a stringbuilder
    Dim res As StringBuilder
    res.Initialize 
    'make content uppercase
    content = content.ToUpperCase
    'length of the result
    Dim slen As Int = content.Length
    Dim i As Int = 0
    For i = 0 To slen - 1
        'get the content at position
        Dim code_in As String = content.CharAt(i)
        If mkeys.ContainsKey(code_in) Then
             Dim code_out As String = mkeys.Get(code_in)
            res.Append(code_out)
        End If
    Next
    Return res.ToString
End Sub