Конвертер величин

Private Sub cmdConv_Click()
Dim Cnv As Byte
If cmbEd1.Text = "метры" And cmbEd2.Text = "миллиметры" Then Cnv = 1
If cmbEd1.Text = "метры" And cmbEd2.Text = "версты" Then Cnv = 2
If cmbEd1.Text = "метры" And cmbEd2.Text = "мили" Then Cnv = 3
If cmbEd1.Text = "метры" And cmbEd2.Text = "ярды" Then Cnv = 4
If cmbEd1.Text = "метры" And cmbEd2.Text = "фунты" Then Cnv = 5
If cmbEd1.Text = "" Or cmbEd2.Text = "" Or cmbEd1.Text = cmbEd2.Text Or txtKol.Text = "" Or Val(txtKol) = 0 Then
txtRez.Text = ""
Cnv = 0
End If
 
If Cnv = 1 Then txtRez.Text = txtKol.Text * 1000
If Cnv = 2 Then txtRez.Text = txtKol.Text * 0.000937
If Cnv = 3 Then txtRez.Text = txtKol.Text * 0.000621
If Cnv = 4 Then txtRez.Text = txtKol.Text * 1.094
If Cnv = 5 Then txtRez.Text = txtKol.Text * 0.3048
End Sub
 
Private Sub Command1_Click()
End
End Sub

Private Sub TextBox1_Change()
If IsNumeric(TextBox1) Then
  TextBox2 = TextBox1 / ComboBox1 * ComboBox2
Else
  TextBox2 = "?"
End If
End Sub