Visual Basic - Validación de solo letras y número (textbox)

Private Sub Text1_KeyPress(KeyAscii As Integer)

If (KeyAscii >= 97) And (KeyAscii < 122) Or (KeyAscii >= 65) And (KeyAscii < 90) Then

  MsgBox "Nada de letras"

  KeyAscii = 8

End If

End Sub

Private Sub Text1_KeyPress(KeyAscii As Integer)

        If (KeyAscii >= 48) And (KeyAscii <= 57) Then

                   MsgBox "Nada de numeros"

                   KeyAscii = 8

        end if

End Sub

Private Sub Text1_KeyPress(KeyAscii As Integer)

If (KeyAscii >= 33) And (KeyAscii <= 47) Or (KeyAscii >= 58) And (KeyAscii <= 100) Or _

   (KeyAscii >= 91) And (KeyAscii <= 96) Or (KeyAscii >= 123) And (KeyAscii <= 126) Then

    MsgBox "Nada de simbolos"

    KeyAscii = 8

End If

End Sub

Private Sub textbox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles textbox.KeyPress

    If Char.IsDigit(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsControl(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsSymbol(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsSeparator(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsWhiteSpace(e.KeyChar) Then

        e.Handled = False

    Else

        e.Handled = True

    End If

    Me.textbox.Text = Trim(Replace(Me.textbox.Text, "  ", " "))

    textbox.Select(textbox.Text.Length, 0)

End Sub

Private Sub textbox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles textbox.KeyPress

    If Char.IsLetter(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsControl(e.KeyChar) Then

        e.Handled = False

    ElseIf Char.IsSeparator(e.KeyChar) Then

        e.Handled = False

    Else

        e.Handled = True

    End If

    Me.textbox.Text = Trim(Replace(Me.textbox.Text, " ", ""))

    textbox.Select(textbox.Text.Length, 0)

End Sub

Private Sub ENTRAtextbox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles EntraTextBox.KeyPress

        If Char.IsPunctuation(e.KeyChar) Or Char.IsDigit(e.KeyChar) Then

            e.Handled = False

        ElseIf Char.IsControl(e.KeyChar) Then

            e.Handled = False

        ElseIf Char.IsSymbol(e.KeyChar) Then

            e.Handled = False

        ElseIf Char.IsSeparator(e.KeyChar) Then

            e.Handled = False

        ElseIf Char.IsWhiteSpace(e.KeyChar) Then

            e.Handled = False

        Else

            e.Handled = True

        End If

        Me.EntraTextBox.Text = Trim(Replace(Me.EntraTextBox.Text, "  ", " "))

        EntraTextBox.Select(EntraTextBox.Text.Length, 0)

    End Sub

Private Sub txtCuadro_KeyPress(sender As Object, e As KeyPressEventArgs) Handles txtCuadro.KeyPress

    If Not (IsNumeric(e.KeyChar)) And Asc(e.KeyChar) <> 8 Then

        e.Handled = True

    End If

End Sub

Private Sub txt_casilla_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)

    If Not IsNumeric(Chr(KeyAscii.value)) Then

        KeyAscii.value = 8

    End If

End Sub

Private Sub txt_casilla_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)

    If IsNumeric(Chr(KeyAscii.value)) Then

        KeyAscii.value = 8

    End If

End Sub

If Char.IsDigit(e.KeyChar) Then

    e.Handled = False

ElseIf e.KeyChar = ChrW(8) Then 'BACKSPACE

    e.Handled = False

ElseIf e.KeyChar >= ChrW(97) And e.KeyChar < ChrW(122) Or e.KeyChar >= ChrW(65) And e.KeyChar < ChrW(90) Then

    e.Handled = False

Else

    e.Handled = True

End If