code for random password generation

    Private Sub btnGenerate_Click(sender As Object, e As EventArgs) Handles btnGenerate.Click
        ' First we must check that the number in
        ' txtLength.Text property is a real integer number or not
        If Not IsNumeric(txtLength.Text) Then
            MessageBox.Show("Password length must be a whole nmber")
            txtLength.Focus()
            Exit Sub
        End If

        ' It was an integer so we can keep on
        ' now we check that the pass length is not below 6
        ' because we want the password to be minimum 6 char long
        If CInt(txtLength.Text) < 6 Then
            MessageBox.Show("Password length must be 6 or higher")
            txtLength.Focus()
            Exit Sub
        End If

        ' okay, so the length is now a number and is 6 or more char lonng
        ' so we can begin the password generation

        ' setup som variables.
        Dim RandomClass As New Random()
        Dim UsableChars() As String = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"}
        Dim SpecialChars() As String = {"=", "+", "-", "_", "(", ")", "*", "&", "^", "%", "$", "#", "@", "!", "~", "`", "{", "}", "[", "]", ":", "'", "?", "/", ">", ".", ",", "<"}
        Dim FinalPassword As String = ""
        Dim index As Integer = 0
        Dim PassLength = CInt(txtLength.Text)
        Dim i As Integer

        For i = 1 To PassLength
            index = RandomClass.Next(0, UsableChars.Length() - 1)
            FinalPassword += UsableChars(index)
        Next

        txtPassword.Text = FinalPassword
    End Sub