title: VB - Calculation always returns a 0
body: <p>When I change two strings to a double, then subtract them, the answer is always 0. does anyone know a way to fix this?</p>
  
  <pre><code>    Dim TotalCashNum As Double
      Dim InsertCoinNum As Double
      Dim NewTotalCash As Double
  
      InsertCoinsTextBox.Text = Convert.ToDouble(InsertCoinNum)
      TotalCash.Text = Convert.ToDouble(TotalCashNum)
      NewTotalCash = TotalCashNum - InsertCoinNum
      MsgBox(NewTotalCash)
  </code></pre>
  
  <p>Thanks in advance</p>